what is your hypothesis (or hypotheses) for this experiment

Bipolar Disorder
Therapy Center
When To See a Therapist
Types of Therapy
Best Online Therapy
Best Couples Therapy
Best Family Therapy
Managing Stress
Sleep and Dreaming
Understanding Emotions
Self-Improvement
Healthy Relationships
Student Resources
Personality Types
Guided Meditations
Verywell Mind Insights
2024 Verywell Mind 25
Mental Health in the Classroom
Editorial Process
Meet Our Review Board
Crisis Support

How to Write a Great Hypothesis

Hypothesis Definition, Format, Examples, and Tips

Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

what is your hypothesis (or hypotheses) for this experiment

Amy Morin, LCSW, is a psychotherapist and international bestselling author. Her books, including "13 Things Mentally Strong People Don't Do," have been translated into more than 40 languages. Her TEDx talk, "The Secret of Becoming Mentally Strong," is one of the most viewed talks of all time.

Verywell / Alex Dos Diaz

The Scientific Method

Hypothesis Format

Falsifiability of a hypothesis.

Operationalization

Hypothesis Types

Hypotheses examples.

Collecting Data

A hypothesis is a tentative statement about the relationship between two or more variables. It is a specific, testable prediction about what you expect to happen in a study. It is a preliminary answer to your question that helps guide the research process.

Consider a study designed to examine the relationship between sleep deprivation and test performance. The hypothesis might be: "This study is designed to assess the hypothesis that sleep-deprived people will perform worse on a test than individuals who are not sleep-deprived."

At a Glance

A hypothesis is crucial to scientific research because it offers a clear direction for what the researchers are looking to find. This allows them to design experiments to test their predictions and add to our scientific knowledge about the world. This article explores how a hypothesis is used in psychology research, how to write a good hypothesis, and the different types of hypotheses you might use.

The Hypothesis in the Scientific Method

In the scientific method , whether it involves research in psychology, biology, or some other area, a hypothesis represents what the researchers think will happen in an experiment. The scientific method involves the following steps:

Forming a question
Performing background research
Creating a hypothesis
Designing an experiment
Collecting data
Analyzing the results
Drawing conclusions
Communicating the results

The hypothesis is a prediction, but it involves more than a guess. Most of the time, the hypothesis begins with a question which is then explored through background research. At this point, researchers then begin to develop a testable hypothesis.

Unless you are creating an exploratory study, your hypothesis should always explain what you expect to happen.

In a study exploring the effects of a particular drug, the hypothesis might be that researchers expect the drug to have some type of effect on the symptoms of a specific illness. In psychology, the hypothesis might focus on how a certain aspect of the environment might influence a particular behavior.

Remember, a hypothesis does not have to be correct. While the hypothesis predicts what the researchers expect to see, the goal of the research is to determine whether this guess is right or wrong. When conducting an experiment, researchers might explore numerous factors to determine which ones might contribute to the ultimate outcome.

In many cases, researchers may find that the results of an experiment do not support the original hypothesis. When writing up these results, the researchers might suggest other options that should be explored in future studies.

In many cases, researchers might draw a hypothesis from a specific theory or build on previous research. For example, prior research has shown that stress can impact the immune system. So a researcher might hypothesize: "People with high-stress levels will be more likely to contract a common cold after being exposed to the virus than people who have low-stress levels."

In other instances, researchers might look at commonly held beliefs or folk wisdom. "Birds of a feather flock together" is one example of folk adage that a psychologist might try to investigate. The researcher might pose a specific hypothesis that "People tend to select romantic partners who are similar to them in interests and educational level."

Elements of a Good Hypothesis

So how do you write a good hypothesis? When trying to come up with a hypothesis for your research or experiments, ask yourself the following questions:

Is your hypothesis based on your research on a topic?
Can your hypothesis be tested?
Does your hypothesis include independent and dependent variables?

Before you come up with a specific hypothesis, spend some time doing background research. Once you have completed a literature review, start thinking about potential questions you still have. Pay attention to the discussion section in the journal articles you read . Many authors will suggest questions that still need to be explored.

How to Formulate a Good Hypothesis

To form a hypothesis, you should take these steps:

Collect as many observations about a topic or problem as you can.
Evaluate these observations and look for possible causes of the problem.
Create a list of possible explanations that you might want to explore.
After you have developed some possible hypotheses, think of ways that you could confirm or disprove each hypothesis through experimentation. This is known as falsifiability.

In the scientific method , falsifiability is an important part of any valid hypothesis. In order to test a claim scientifically, it must be possible that the claim could be proven false.

Students sometimes confuse the idea of falsifiability with the idea that it means that something is false, which is not the case. What falsifiability means is that if something was false, then it is possible to demonstrate that it is false.

One of the hallmarks of pseudoscience is that it makes claims that cannot be refuted or proven false.

The Importance of Operational Definitions

A variable is a factor or element that can be changed and manipulated in ways that are observable and measurable. However, the researcher must also define how the variable will be manipulated and measured in the study.

Operational definitions are specific definitions for all relevant factors in a study. This process helps make vague or ambiguous concepts detailed and measurable.

For example, a researcher might operationally define the variable " test anxiety " as the results of a self-report measure of anxiety experienced during an exam. A "study habits" variable might be defined by the amount of studying that actually occurs as measured by time.

These precise descriptions are important because many things can be measured in various ways. Clearly defining these variables and how they are measured helps ensure that other researchers can replicate your results.

Replicability

One of the basic principles of any type of scientific research is that the results must be replicable.

Replication means repeating an experiment in the same way to produce the same results. By clearly detailing the specifics of how the variables were measured and manipulated, other researchers can better understand the results and repeat the study if needed.

Some variables are more difficult than others to define. For example, how would you operationally define a variable such as aggression ? For obvious ethical reasons, researchers cannot create a situation in which a person behaves aggressively toward others.

To measure this variable, the researcher must devise a measurement that assesses aggressive behavior without harming others. The researcher might utilize a simulated task to measure aggressiveness in this situation.

Hypothesis Checklist

Does your hypothesis focus on something that you can actually test?
Does your hypothesis include both an independent and dependent variable?
Can you manipulate the variables?
Can your hypothesis be tested without violating ethical standards?

The hypothesis you use will depend on what you are investigating and hoping to find. Some of the main types of hypotheses that you might use include:

Simple hypothesis : This type of hypothesis suggests there is a relationship between one independent variable and one dependent variable.
Complex hypothesis : This type suggests a relationship between three or more variables, such as two independent and dependent variables.
Null hypothesis : This hypothesis suggests no relationship exists between two or more variables.
Alternative hypothesis : This hypothesis states the opposite of the null hypothesis.
Statistical hypothesis : This hypothesis uses statistical analysis to evaluate a representative population sample and then generalizes the findings to the larger group.
Logical hypothesis : This hypothesis assumes a relationship between variables without collecting data or evidence.

A hypothesis often follows a basic format of "If {this happens} then {this will happen}." One way to structure your hypothesis is to describe what will happen to the dependent variable if you change the independent variable .

The basic format might be: "If {these changes are made to a certain independent variable}, then we will observe {a change in a specific dependent variable}."

A few examples of simple hypotheses:

"Students who eat breakfast will perform better on a math exam than students who do not eat breakfast."
"Students who experience test anxiety before an English exam will get lower scores than students who do not experience test anxiety."
"Motorists who talk on the phone while driving will be more likely to make errors on a driving course than those who do not talk on the phone."
"Children who receive a new reading intervention will have higher reading scores than students who do not receive the intervention."

Examples of a complex hypothesis include:

"People with high-sugar diets and sedentary activity levels are more likely to develop depression."
"Younger people who are regularly exposed to green, outdoor areas have better subjective well-being than older adults who have limited exposure to green spaces."

Examples of a null hypothesis include:

"There is no difference in anxiety levels between people who take St. John's wort supplements and those who do not."
"There is no difference in scores on a memory recall task between children and adults."
"There is no difference in aggression levels between children who play first-person shooter games and those who do not."

Examples of an alternative hypothesis:

"People who take St. John's wort supplements will have less anxiety than those who do not."
"Adults will perform better on a memory task than children."
"Children who play first-person shooter games will show higher levels of aggression than children who do not."

Collecting Data on Your Hypothesis

Once a researcher has formed a testable hypothesis, the next step is to select a research design and start collecting data. The research method depends largely on exactly what they are studying. There are two basic types of research methods: descriptive research and experimental research.

Descriptive Research Methods

Descriptive research such as case studies , naturalistic observations , and surveys are often used when conducting an experiment is difficult or impossible. These methods are best used to describe different aspects of a behavior or psychological phenomenon.

Once a researcher has collected data using descriptive methods, a correlational study can examine how the variables are related. This research method might be used to investigate a hypothesis that is difficult to test experimentally.

Experimental Research Methods

Experimental methods are used to demonstrate causal relationships between variables. In an experiment, the researcher systematically manipulates a variable of interest (known as the independent variable) and measures the effect on another variable (known as the dependent variable).

Unlike correlational studies, which can only be used to determine if there is a relationship between two variables, experimental methods can be used to determine the actual nature of the relationship—whether changes in one variable actually cause another to change.

The hypothesis is a critical part of any scientific exploration. It represents what researchers expect to find in a study or experiment. In situations where the hypothesis is unsupported by the research, the research still has value. Such research helps us better understand how different aspects of the natural world relate to one another. It also helps us develop new hypotheses that can then be tested in the future.

Thompson WH, Skau S. On the scope of scientific hypotheses . R Soc Open Sci . 2023;10(8):230607. doi:10.1098/rsos.230607

Taran S, Adhikari NKJ, Fan E. Falsifiability in medicine: what clinicians can learn from Karl Popper [published correction appears in Intensive Care Med. 2021 Jun 17;:]. Intensive Care Med . 2021;47(9):1054-1056. doi:10.1007/s00134-021-06432-z

Eyler AA. Research Methods for Public Health . 1st ed. Springer Publishing Company; 2020. doi:10.1891/9780826182067.0004

Nosek BA, Errington TM. What is replication ? PLoS Biol . 2020;18(3):e3000691. doi:10.1371/journal.pbio.3000691

Aggarwal R, Ranganathan P. Study designs: Part 2 - Descriptive studies . Perspect Clin Res . 2019;10(1):34-36. doi:10.4103/picr.PICR_154_18

Nevid J. Psychology: Concepts and Applications. Wadworth, 2013.

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

Home » What is a Hypothesis – Types, Examples and Writing Guide

What is a Hypothesis – Types, Examples and Writing Guide

Table of Contents

Definition:

Hypothesis is an educated guess or proposed explanation for a phenomenon, based on some initial observations or data. It is a tentative statement that can be tested and potentially proven or disproven through further investigation and experimentation.

Hypothesis is often used in scientific research to guide the design of experiments and the collection and analysis of data. It is an essential element of the scientific method, as it allows researchers to make predictions about the outcome of their experiments and to test those predictions to determine their accuracy.

Types of Hypothesis

Types of Hypothesis are as follows:

Research Hypothesis

A research hypothesis is a statement that predicts a relationship between variables. It is usually formulated as a specific statement that can be tested through research, and it is often used in scientific research to guide the design of experiments.

Null Hypothesis

The null hypothesis is a statement that assumes there is no significant difference or relationship between variables. It is often used as a starting point for testing the research hypothesis, and if the results of the study reject the null hypothesis, it suggests that there is a significant difference or relationship between variables.

Alternative Hypothesis

An alternative hypothesis is a statement that assumes there is a significant difference or relationship between variables. It is often used as an alternative to the null hypothesis and is tested against the null hypothesis to determine which statement is more accurate.

Directional Hypothesis

A directional hypothesis is a statement that predicts the direction of the relationship between variables. For example, a researcher might predict that increasing the amount of exercise will result in a decrease in body weight.

Non-directional Hypothesis

A non-directional hypothesis is a statement that predicts the relationship between variables but does not specify the direction. For example, a researcher might predict that there is a relationship between the amount of exercise and body weight, but they do not specify whether increasing or decreasing exercise will affect body weight.

Statistical Hypothesis

A statistical hypothesis is a statement that assumes a particular statistical model or distribution for the data. It is often used in statistical analysis to test the significance of a particular result.

Composite Hypothesis

A composite hypothesis is a statement that assumes more than one condition or outcome. It can be divided into several sub-hypotheses, each of which represents a different possible outcome.

Empirical Hypothesis

An empirical hypothesis is a statement that is based on observed phenomena or data. It is often used in scientific research to develop theories or models that explain the observed phenomena.

Simple Hypothesis

A simple hypothesis is a statement that assumes only one outcome or condition. It is often used in scientific research to test a single variable or factor.

Complex Hypothesis

A complex hypothesis is a statement that assumes multiple outcomes or conditions. It is often used in scientific research to test the effects of multiple variables or factors on a particular outcome.

Applications of Hypothesis

Hypotheses are used in various fields to guide research and make predictions about the outcomes of experiments or observations. Here are some examples of how hypotheses are applied in different fields:

Science : In scientific research, hypotheses are used to test the validity of theories and models that explain natural phenomena. For example, a hypothesis might be formulated to test the effects of a particular variable on a natural system, such as the effects of climate change on an ecosystem.
Medicine : In medical research, hypotheses are used to test the effectiveness of treatments and therapies for specific conditions. For example, a hypothesis might be formulated to test the effects of a new drug on a particular disease.
Psychology : In psychology, hypotheses are used to test theories and models of human behavior and cognition. For example, a hypothesis might be formulated to test the effects of a particular stimulus on the brain or behavior.
Sociology : In sociology, hypotheses are used to test theories and models of social phenomena, such as the effects of social structures or institutions on human behavior. For example, a hypothesis might be formulated to test the effects of income inequality on crime rates.
Business : In business research, hypotheses are used to test the validity of theories and models that explain business phenomena, such as consumer behavior or market trends. For example, a hypothesis might be formulated to test the effects of a new marketing campaign on consumer buying behavior.
Engineering : In engineering, hypotheses are used to test the effectiveness of new technologies or designs. For example, a hypothesis might be formulated to test the efficiency of a new solar panel design.

How to write a Hypothesis

Here are the steps to follow when writing a hypothesis:

Identify the Research Question

The first step is to identify the research question that you want to answer through your study. This question should be clear, specific, and focused. It should be something that can be investigated empirically and that has some relevance or significance in the field.

Conduct a Literature Review

Before writing your hypothesis, it’s essential to conduct a thorough literature review to understand what is already known about the topic. This will help you to identify the research gap and formulate a hypothesis that builds on existing knowledge.

Determine the Variables

The next step is to identify the variables involved in the research question. A variable is any characteristic or factor that can vary or change. There are two types of variables: independent and dependent. The independent variable is the one that is manipulated or changed by the researcher, while the dependent variable is the one that is measured or observed as a result of the independent variable.

Formulate the Hypothesis

Based on the research question and the variables involved, you can now formulate your hypothesis. A hypothesis should be a clear and concise statement that predicts the relationship between the variables. It should be testable through empirical research and based on existing theory or evidence.

Write the Null Hypothesis

The null hypothesis is the opposite of the alternative hypothesis, which is the hypothesis that you are testing. The null hypothesis states that there is no significant difference or relationship between the variables. It is important to write the null hypothesis because it allows you to compare your results with what would be expected by chance.

Refine the Hypothesis

After formulating the hypothesis, it’s important to refine it and make it more precise. This may involve clarifying the variables, specifying the direction of the relationship, or making the hypothesis more testable.

Examples of Hypothesis

Here are a few examples of hypotheses in different fields:

Psychology : “Increased exposure to violent video games leads to increased aggressive behavior in adolescents.”
Biology : “Higher levels of carbon dioxide in the atmosphere will lead to increased plant growth.”
Sociology : “Individuals who grow up in households with higher socioeconomic status will have higher levels of education and income as adults.”
Education : “Implementing a new teaching method will result in higher student achievement scores.”
Marketing : “Customers who receive a personalized email will be more likely to make a purchase than those who receive a generic email.”
Physics : “An increase in temperature will cause an increase in the volume of a gas, assuming all other variables remain constant.”
Medicine : “Consuming a diet high in saturated fats will increase the risk of developing heart disease.”

Purpose of Hypothesis

The purpose of a hypothesis is to provide a testable explanation for an observed phenomenon or a prediction of a future outcome based on existing knowledge or theories. A hypothesis is an essential part of the scientific method and helps to guide the research process by providing a clear focus for investigation. It enables scientists to design experiments or studies to gather evidence and data that can support or refute the proposed explanation or prediction.

The formulation of a hypothesis is based on existing knowledge, observations, and theories, and it should be specific, testable, and falsifiable. A specific hypothesis helps to define the research question, which is important in the research process as it guides the selection of an appropriate research design and methodology. Testability of the hypothesis means that it can be proven or disproven through empirical data collection and analysis. Falsifiability means that the hypothesis should be formulated in such a way that it can be proven wrong if it is incorrect.

In addition to guiding the research process, the testing of hypotheses can lead to new discoveries and advancements in scientific knowledge. When a hypothesis is supported by the data, it can be used to develop new theories or models to explain the observed phenomenon. When a hypothesis is not supported by the data, it can help to refine existing theories or prompt the development of new hypotheses to explain the phenomenon.

When to use Hypothesis

Here are some common situations in which hypotheses are used:

In scientific research , hypotheses are used to guide the design of experiments and to help researchers make predictions about the outcomes of those experiments.
In social science research , hypotheses are used to test theories about human behavior, social relationships, and other phenomena.
I n business , hypotheses can be used to guide decisions about marketing, product development, and other areas. For example, a hypothesis might be that a new product will sell well in a particular market, and this hypothesis can be tested through market research.

Characteristics of Hypothesis

Here are some common characteristics of a hypothesis:

Testable : A hypothesis must be able to be tested through observation or experimentation. This means that it must be possible to collect data that will either support or refute the hypothesis.
Falsifiable : A hypothesis must be able to be proven false if it is not supported by the data. If a hypothesis cannot be falsified, then it is not a scientific hypothesis.
Clear and concise : A hypothesis should be stated in a clear and concise manner so that it can be easily understood and tested.
Based on existing knowledge : A hypothesis should be based on existing knowledge and research in the field. It should not be based on personal beliefs or opinions.
Specific : A hypothesis should be specific in terms of the variables being tested and the predicted outcome. This will help to ensure that the research is focused and well-designed.
Tentative: A hypothesis is a tentative statement or assumption that requires further testing and evidence to be confirmed or refuted. It is not a final conclusion or assertion.
Relevant : A hypothesis should be relevant to the research question or problem being studied. It should address a gap in knowledge or provide a new perspective on the issue.

Advantages of Hypothesis

Hypotheses have several advantages in scientific research and experimentation:

Guides research: A hypothesis provides a clear and specific direction for research. It helps to focus the research question, select appropriate methods and variables, and interpret the results.
Predictive powe r: A hypothesis makes predictions about the outcome of research, which can be tested through experimentation. This allows researchers to evaluate the validity of the hypothesis and make new discoveries.
Facilitates communication: A hypothesis provides a common language and framework for scientists to communicate with one another about their research. This helps to facilitate the exchange of ideas and promotes collaboration.
Efficient use of resources: A hypothesis helps researchers to use their time, resources, and funding efficiently by directing them towards specific research questions and methods that are most likely to yield results.
Provides a basis for further research: A hypothesis that is supported by data provides a basis for further research and exploration. It can lead to new hypotheses, theories, and discoveries.
Increases objectivity: A hypothesis can help to increase objectivity in research by providing a clear and specific framework for testing and interpreting results. This can reduce bias and increase the reliability of research findings.

Limitations of Hypothesis

Some Limitations of the Hypothesis are as follows:

Limited to observable phenomena: Hypotheses are limited to observable phenomena and cannot account for unobservable or intangible factors. This means that some research questions may not be amenable to hypothesis testing.
May be inaccurate or incomplete: Hypotheses are based on existing knowledge and research, which may be incomplete or inaccurate. This can lead to flawed hypotheses and erroneous conclusions.
May be biased: Hypotheses may be biased by the researcher’s own beliefs, values, or assumptions. This can lead to selective interpretation of data and a lack of objectivity in research.
Cannot prove causation: A hypothesis can only show a correlation between variables, but it cannot prove causation. This requires further experimentation and analysis.
Limited to specific contexts: Hypotheses are limited to specific contexts and may not be generalizable to other situations or populations. This means that results may not be applicable in other contexts or may require further testing.
May be affected by chance : Hypotheses may be affected by chance or random variation, which can obscure or distort the true relationship between variables.

About the author

Muhammad Hassan

Researcher, Academic Writer, Web developer

Data Collection – Methods Types and Examples

Delimitations in Research – Types, Examples and...

Research Process – Steps, Examples and Tips

Research Design – Types, Methods and Examples

Institutional Review Board – Application Sample...

Evaluating Research – Process, Examples and...

Module 1: Introduction to Biology

Experiments and hypotheses, learning outcomes.

Form a hypothesis and use it to design a scientific experiment

Now we’ll focus on the methods of scientific inquiry. Science often involves making observations and developing hypotheses. Experiments and further observations are often used to test the hypotheses.

A scientific experiment is a carefully organized procedure in which the scientist intervenes in a system to change something, then observes the result of the change. Scientific inquiry often involves doing experiments, though not always. For example, a scientist studying the mating behaviors of ladybugs might begin with detailed observations of ladybugs mating in their natural habitats. While this research may not be experimental, it is scientific: it involves careful and verifiable observation of the natural world. The same scientist might then treat some of the ladybugs with a hormone hypothesized to trigger mating and observe whether these ladybugs mated sooner or more often than untreated ones. This would qualify as an experiment because the scientist is now making a change in the system and observing the effects.

Forming a Hypothesis

When conducting scientific experiments, researchers develop hypotheses to guide experimental design. A hypothesis is a suggested explanation that is both testable and falsifiable. You must be able to test your hypothesis, and it must be possible to prove your hypothesis true or false.

For example, Michael observes that maple trees lose their leaves in the fall. He might then propose a possible explanation for this observation: “cold weather causes maple trees to lose their leaves in the fall.” This statement is testable. He could grow maple trees in a warm enclosed environment such as a greenhouse and see if their leaves still dropped in the fall. The hypothesis is also falsifiable. If the leaves still dropped in the warm environment, then clearly temperature was not the main factor in causing maple leaves to drop in autumn.

In the Try It below, you can practice recognizing scientific hypotheses. As you consider each statement, try to think as a scientist would: can I test this hypothesis with observations or experiments? Is the statement falsifiable? If the answer to either of these questions is “no,” the statement is not a valid scientific hypothesis.

Practice Questions

Determine whether each following statement is a scientific hypothesis.

Air pollution from automobile exhaust can trigger symptoms in people with asthma.

No. This statement is not testable or falsifiable.
No. This statement is not testable.
No. This statement is not falsifiable.
Yes. This statement is testable and falsifiable.

Natural disasters, such as tornadoes, are punishments for bad thoughts and behaviors.

a: No. This statement is not testable or falsifiable. “Bad thoughts and behaviors” are excessively vague and subjective variables that would be impossible to measure or agree upon in a reliable way. The statement might be “falsifiable” if you came up with a counterexample: a “wicked” place that was not punished by a natural disaster. But some would question whether the people in that place were really wicked, and others would continue to predict that a natural disaster was bound to strike that place at some point. There is no reason to suspect that people’s immoral behavior affects the weather unless you bring up the intervention of a supernatural being, making this idea even harder to test.

Testing a Vaccine

Let’s examine the scientific process by discussing an actual scientific experiment conducted by researchers at the University of Washington. These researchers investigated whether a vaccine may reduce the incidence of the human papillomavirus (HPV). The experimental process and results were published in an article titled, “ A controlled trial of a human papillomavirus type 16 vaccine .”

Preliminary observations made by the researchers who conducted the HPV experiment are listed below:

Human papillomavirus (HPV) is the most common sexually transmitted virus in the United States.
There are about 40 different types of HPV. A significant number of people that have HPV are unaware of it because many of these viruses cause no symptoms.
Some types of HPV can cause cervical cancer.
About 4,000 women a year die of cervical cancer in the United States.

Practice Question

Researchers have developed a potential vaccine against HPV and want to test it. What is the first testable hypothesis that the researchers should study?

HPV causes cervical cancer.
People should not have unprotected sex with many partners.
People who get the vaccine will not get HPV.
The HPV vaccine will protect people against cancer.

Experimental Design

You’ve successfully identified a hypothesis for the University of Washington’s study on HPV: People who get the HPV vaccine will not get HPV.

The next step is to design an experiment that will test this hypothesis. There are several important factors to consider when designing a scientific experiment. First, scientific experiments must have an experimental group. This is the group that receives the experimental treatment necessary to address the hypothesis.

The experimental group receives the vaccine, but how can we know if the vaccine made a difference? Many things may change HPV infection rates in a group of people over time. To clearly show that the vaccine was effective in helping the experimental group, we need to include in our study an otherwise similar control group that does not get the treatment. We can then compare the two groups and determine if the vaccine made a difference. The control group shows us what happens in the absence of the factor under study.

However, the control group cannot get “nothing.” Instead, the control group often receives a placebo. A placebo is a procedure that has no expected therapeutic effect—such as giving a person a sugar pill or a shot containing only plain saline solution with no drug. Scientific studies have shown that the “placebo effect” can alter experimental results because when individuals are told that they are or are not being treated, this knowledge can alter their actions or their emotions, which can then alter the results of the experiment.

Moreover, if the doctor knows which group a patient is in, this can also influence the results of the experiment. Without saying so directly, the doctor may show—through body language or other subtle cues—their views about whether the patient is likely to get well. These errors can then alter the patient’s experience and change the results of the experiment. Therefore, many clinical studies are “double blind.” In these studies, neither the doctor nor the patient knows which group the patient is in until all experimental results have been collected.

Both placebo treatments and double-blind procedures are designed to prevent bias. Bias is any systematic error that makes a particular experimental outcome more or less likely. Errors can happen in any experiment: people make mistakes in measurement, instruments fail, computer glitches can alter data. But most such errors are random and don’t favor one outcome over another. Patients’ belief in a treatment can make it more likely to appear to “work.” Placebos and double-blind procedures are used to level the playing field so that both groups of study subjects are treated equally and share similar beliefs about their treatment.

The scientists who are researching the effectiveness of the HPV vaccine will test their hypothesis by separating 2,392 young women into two groups: the control group and the experimental group. Answer the following questions about these two groups.

This group is given a placebo.
This group is deliberately infected with HPV.
This group is given nothing.
This group is given the HPV vaccine.
a: This group is given a placebo. A placebo will be a shot, just like the HPV vaccine, but it will have no active ingredient. It may change peoples’ thinking or behavior to have such a shot given to them, but it will not stimulate the immune systems of the subjects in the same way as predicted for the vaccine itself.
d: This group is given the HPV vaccine. The experimental group will receive the HPV vaccine and researchers will then be able to see if it works, when compared to the control group.

Experimental Variables

A variable is a characteristic of a subject (in this case, of a person in the study) that can vary over time or among individuals. Sometimes a variable takes the form of a category, such as male or female; often a variable can be measured precisely, such as body height. Ideally, only one variable is different between the control group and the experimental group in a scientific experiment. Otherwise, the researchers will not be able to determine which variable caused any differences seen in the results. For example, imagine that the people in the control group were, on average, much more sexually active than the people in the experimental group. If, at the end of the experiment, the control group had a higher rate of HPV infection, could you confidently determine why? Maybe the experimental subjects were protected by the vaccine, but maybe they were protected by their low level of sexual contact.

To avoid this situation, experimenters make sure that their subject groups are as similar as possible in all variables except for the variable that is being tested in the experiment. This variable, or factor, will be deliberately changed in the experimental group. The one variable that is different between the two groups is called the independent variable. An independent variable is known or hypothesized to cause some outcome. Imagine an educational researcher investigating the effectiveness of a new teaching strategy in a classroom. The experimental group receives the new teaching strategy, while the control group receives the traditional strategy. It is the teaching strategy that is the independent variable in this scenario. In an experiment, the independent variable is the variable that the scientist deliberately changes or imposes on the subjects.

Dependent variables are known or hypothesized consequences; they are the effects that result from changes or differences in an independent variable. In an experiment, the dependent variables are those that the scientist measures before, during, and particularly at the end of the experiment to see if they have changed as expected. The dependent variable must be stated so that it is clear how it will be observed or measured. Rather than comparing “learning” among students (which is a vague and difficult to measure concept), an educational researcher might choose to compare test scores, which are very specific and easy to measure.

In any real-world example, many, many variables MIGHT affect the outcome of an experiment, yet only one or a few independent variables can be tested. Other variables must be kept as similar as possible between the study groups and are called control variables . For our educational research example, if the control group consisted only of people between the ages of 18 and 20 and the experimental group contained people between the ages of 30 and 35, we would not know if it was the teaching strategy or the students’ ages that played a larger role in the results. To avoid this problem, a good study will be set up so that each group contains students with a similar age profile. In a well-designed educational research study, student age will be a controlled variable, along with other possibly important factors like gender, past educational achievement, and pre-existing knowledge of the subject area.

What is the independent variable in this experiment?

Sex (all of the subjects will be female)
Presence or absence of the HPV vaccine
Presence or absence of HPV (the virus)

List three control variables other than age.

What is the dependent variable in this experiment?

Sex (male or female)
Rates of HPV infection
Age (years)
Revision and adaptation. Authored by : Shelli Carter and Lumen Learning. Provided by : Lumen Learning. License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
Scientific Inquiry. Provided by : Open Learning Initiative. Located at : https://oli.cmu.edu/jcourse/workbook/activity/page?context=434a5c2680020ca6017c03488572e0f8 . Project : Introduction to Biology (Open + Free). License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike

school Campus Bookshelves
menu_book Bookshelves
perm_media Learning Objects
login Login
how_to_reg Request Instructor Account
hub Instructor Commons

Margin Size

Download Page (PDF)
Download Full Book (PDF)
Periodic Table
Physics Constants
Scientific Calculator
Reference & Cite
Tools expand_more
Readability

selected template will load here

This action is not available.

4.14: Experiments and Hypotheses

Last updated
Save as PDF
Page ID 43806

$ \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } $

$ \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} $

$ \newcommand{\id}{\mathrm{id}}$ $ \newcommand{\Span}{\mathrm{span}}$

( \newcommand{\kernel}{\mathrm{null}\,}\) $ \newcommand{\range}{\mathrm{range}\,}$

$ \newcommand{\RealPart}{\mathrm{Re}}$ $ \newcommand{\ImaginaryPart}{\mathrm{Im}}$

$ \newcommand{\Argument}{\mathrm{Arg}}$ $ \newcommand{\norm}[1]{\| #1 \|}$

$ \newcommand{\inner}[2]{\langle #1, #2 \rangle}$

$ \newcommand{\Span}{\mathrm{span}}$

$ \newcommand{\id}{\mathrm{id}}$

$ \newcommand{\kernel}{\mathrm{null}\,}$

$ \newcommand{\range}{\mathrm{range}\,}$

$ \newcommand{\RealPart}{\mathrm{Re}}$

$ \newcommand{\ImaginaryPart}{\mathrm{Im}}$

$ \newcommand{\Argument}{\mathrm{Arg}}$

$ \newcommand{\norm}[1]{\| #1 \|}$

$ \newcommand{\Span}{\mathrm{span}}$ $ \newcommand{\AA}{\unicode[.8,0]{x212B}}$

$ \newcommand{\vectorA}[1]{\vec{#1}} % arrow$

$ \newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow$

$ \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } $

$ \newcommand{\vectorC}[1]{\textbf{#1}} $

$ \newcommand{\vectorD}[1]{\overrightarrow{#1}} $

$ \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} $

$ \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} $

Forming a Hypothesis

Practice Questions

Determine whether each following statement is a scientific hypothesis.

No. This statement is not testable or falsifiable.
No. This statement is not testable.
No. This statement is not falsifiable.
Yes. This statement is testable and falsifiable.

[reveal-answer q=”429550″] Show Answers [/reveal-answer] [hidden-answer a=”429550″]

d: Yes. This statement is testable and falsifiable. This could be tested with a number of different kinds of observations and experiments, and it is possible to gather evidence that indicates that air pollution is not linked with asthma.
a: No. This statement is not testable or falsifiable. “Bad thoughts and behaviors” are excessively vague and subjective variables that would be impossible to measure or agree upon in a reliable way. The statement might be “falsifiable” if you came up with a counterexample: a “wicked” place that was not punished by a natural disaster. But some would question whether the people in that place were really wicked, and others would continue to predict that a natural disaster was bound to strike that place at some point. There is no reason to suspect that people’s immoral behavior affects the weather unless you bring up the intervention of a supernatural being, making this idea even harder to test.

[/hidden-answer]

Testing a Vaccine

Preliminary observations made by the researchers who conducted the HPV experiment are listed below:

Human papillomavirus (HPV) is the most common sexually transmitted virus in the United States.
There are about 40 different types of HPV. A significant number of people that have HPV are unaware of it because many of these viruses cause no symptoms.
Some types of HPV can cause cervical cancer.
About 4,000 women a year die of cervical cancer in the United States.

Practice Question

Researchers have developed a potential vaccine against HPV and want to test it. What is the first testable hypothesis that the researchers should study?

HPV causes cervical cancer.
People should not have unprotected sex with many partners.
People who get the vaccine will not get HPV.
The HPV vaccine will protect people against cancer.

[reveal-answer q=”20917″] Show Answer [/reveal-answer] [hidden-answer a=”20917″]Hypothesis A is not the best choice because this information is already known from previous studies. Hypothesis B is not testable because scientific hypotheses are not value statements; they do not include judgments like “should,” “better than,” etc. Scientific evidence certainly might support this value judgment, but a hypothesis would take a different form: “Having unprotected sex with many partners increases a person’s risk for cervical cancer.” Before the researchers can test if the vaccine protects against cancer (hypothesis D), they want to test if it protects against the virus. This statement will make an excellent hypothesis for the next study. The researchers should first test hypothesis C—whether or not the new vaccine can prevent HPV.[/hidden-answer]

Experimental Design

You’ve successfully identified a hypothesis for the University of Washington’s study on HPV: People who get the HPV vaccine will not get HPV.

Moreover, if the doctor knows which group a patient is in, this can also influence the results of the experiment. Without saying so directly, the doctor may show—through body language or other subtle cues—his or her views about whether the patient is likely to get well. These errors can then alter the patient’s experience and change the results of the experiment. Therefore, many clinical studies are “double blind.” In these studies, neither the doctor nor the patient knows which group the patient is in until all experimental results have been collected.

This group is given a placebo.
This group is deliberately infected with HPV.
This group is given nothing.
This group is given the HPV vaccine.

[reveal-answer q=”918962″] Show Answers [/reveal-answer] [hidden-answer a=”918962″]

a: This group is given a placebo. A placebo will be a shot, just like the HPV vaccine, but it will have no active ingredient. It may change peoples’ thinking or behavior to have such a shot given to them, but it will not stimulate the immune systems of the subjects in the same way as predicted for the vaccine itself.
d: This group is given the HPV vaccine. The experimental group will receive the HPV vaccine and researchers will then be able to see if it works, when compared to the control group.

Experimental Variables

What is the independent variable in this experiment?

Sex (all of the subjects will be female)
Presence or absence of the HPV vaccine
Presence or absence of HPV (the virus)

[reveal-answer q=”68680″]Show Answer[/reveal-answer] [hidden-answer a=”68680″]Answer b. Presence or absence of the HPV vaccine. This is the variable that is different between the control and the experimental groups. All the subjects in this study are female, so this variable is the same in all groups. In a well-designed study, the two groups will be of similar age. The presence or absence of the virus is what the researchers will measure at the end of the experiment. Ideally the two groups will both be HPV-free at the start of the experiment.

List three control variables other than age.

[practice-area rows=”3″][/practice-area] [reveal-answer q=”903121″]Show Answer[/reveal-answer] [hidden-answer a=”903121″]Some possible control variables would be: general health of the women, sexual activity, lifestyle, diet, socioeconomic status, etc.

What is the dependent variable in this experiment?

Sex (male or female)
Rates of HPV infection
Age (years)

[reveal-answer q=”907103″]Show Answer[/reveal-answer] [hidden-answer a=”907103″]Answer b. Rates of HPV infection. The researchers will measure how many individuals got infected with HPV after a given period of time.[/hidden-answer]

Contributors and Attributions

Revision and adaptation. Authored by : Shelli Carter and Lumen Learning. Provided by : Lumen Learning. License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
Scientific Inquiry. Provided by : Open Learning Initiative. Located at : https://oli.cmu.edu/jcourse/workbook/activity/page?context=434a5c2680020ca6017c03488572e0f8 . Project : Introduction to Biology (Open + Free). License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike

Scientific Method: Step 3: HYPOTHESIS

Step 1: QUESTION
Step 2: RESEARCH
Step 3: HYPOTHESIS
Step 4: EXPERIMENT
Step 5: DATA
Step 6: CONCLUSION

Step 3: State your hypothesis

Now it's time to state your hypothesis . The hypothesis is an educated guess as to what will happen during your experiment.

The hypothesis is often written using the words "IF" and "THEN." For example, " If I do not study, then I will fail the test." The "if' and "then" statements reflect your independent and dependent variables .

The hypothesis should relate back to your original question and must be testable .

A word about variables...

Your experiment will include variables to measure and to explain any cause and effect. Below you will find some useful links describing the different types of variables.

"What are independent and dependent variables" NCES
[VIDEO] Biology: Independent vs. Dependent Variables (Nucleus Medical Media) Video explaining independent and dependent variables, with examples.

Resource Links

What is and How to Write a Good Hypothesis in Research? (Elsevier)
Hypothesis brochure from Penn State/Berks

<< Previous: Step 2: RESEARCH
Next: Step 4: EXPERIMENT >>
Last Updated: May 9, 2024 10:59 AM
URL: https://harford.libguides.com/scientific_method

What Is a Hypothesis? (Science)

If...,Then...

Angela Lumsden/Getty Images

Scientific Method
Chemical Laws
Periodic Table
Projects & Experiments
Biochemistry
Physical Chemistry
Medical Chemistry
Chemistry In Everyday Life
Famous Chemists
Activities for Kids
Abbreviations & Acronyms
Weather & Climate
Ph.D., Biomedical Sciences, University of Tennessee at Knoxville
B.A., Physics and Mathematics, Hastings College

A hypothesis (plural hypotheses) is a proposed explanation for an observation. The definition depends on the subject.

In science, a hypothesis is part of the scientific method. It is a prediction or explanation that is tested by an experiment. Observations and experiments may disprove a scientific hypothesis, but can never entirely prove one.

In the study of logic, a hypothesis is an if-then proposition, typically written in the form, "If X , then Y ."

In common usage, a hypothesis is simply a proposed explanation or prediction, which may or may not be tested.

Writing a Hypothesis

Most scientific hypotheses are proposed in the if-then format because it's easy to design an experiment to see whether or not a cause and effect relationship exists between the independent variable and the dependent variable . The hypothesis is written as a prediction of the outcome of the experiment.

Null Hypothesis and Alternative Hypothesis

Statistically, it's easier to show there is no relationship between two variables than to support their connection. So, scientists often propose the null hypothesis . The null hypothesis assumes changing the independent variable will have no effect on the dependent variable.

In contrast, the alternative hypothesis suggests changing the independent variable will have an effect on the dependent variable. Designing an experiment to test this hypothesis can be trickier because there are many ways to state an alternative hypothesis.

For example, consider a possible relationship between getting a good night's sleep and getting good grades. The null hypothesis might be stated: "The number of hours of sleep students get is unrelated to their grades" or "There is no correlation between hours of sleep and grades."

An experiment to test this hypothesis might involve collecting data, recording average hours of sleep for each student and grades. If a student who gets eight hours of sleep generally does better than students who get four hours of sleep or 10 hours of sleep, the hypothesis might be rejected.

But the alternative hypothesis is harder to propose and test. The most general statement would be: "The amount of sleep students get affects their grades." The hypothesis might also be stated as "If you get more sleep, your grades will improve" or "Students who get nine hours of sleep have better grades than those who get more or less sleep."

In an experiment, you can collect the same data, but the statistical analysis is less likely to give you a high confidence limit.

Usually, a scientist starts out with the null hypothesis. From there, it may be possible to propose and test an alternative hypothesis, to narrow down the relationship between the variables.

Example of a Hypothesis

Examples of a hypothesis include:

If you drop a rock and a feather, (then) they will fall at the same rate.
Plants need sunlight in order to live. (if sunlight, then life)
Eating sugar gives you energy. (if sugar, then energy)
White, Jay D. Research in Public Administration . Conn., 1998.
Schick, Theodore, and Lewis Vaughn. How to Think about Weird Things: Critical Thinking for a New Age . McGraw-Hill Higher Education, 2002.
Null Hypothesis Examples
Examples of Independent and Dependent Variables
Difference Between Independent and Dependent Variables
Definition of a Hypothesis
Null Hypothesis Definition and Examples
What Are the Elements of a Good Hypothesis?
Six Steps of the Scientific Method
What Are Examples of a Hypothesis?
Independent Variable Definition and Examples
Understanding Simple vs Controlled Experiments
Scientific Method Flow Chart
What Is a Testable Hypothesis?
Scientific Method Vocabulary Terms
What 'Fail to Reject' Means in a Hypothesis Test
How To Design a Science Fair Experiment
What Is an Experiment? Definition and Design

How to Develop a Good Research Hypothesis

The story of a research study begins by asking a question. Researchers all around the globe are asking curious questions and formulating research hypothesis. However, whether the research study provides an effective conclusion depends on how well one develops a good research hypothesis. Research hypothesis examples could help researchers get an idea as to how to write a good research hypothesis.

This blog will help you understand what is a research hypothesis, its characteristics and, how to formulate a research hypothesis

Table of Contents

What is Hypothesis?

Hypothesis is an assumption or an idea proposed for the sake of argument so that it can be tested. It is a precise, testable statement of what the researchers predict will be outcome of the study. Hypothesis usually involves proposing a relationship between two variables: the independent variable (what the researchers change) and the dependent variable (what the research measures).

What is a Research Hypothesis?

Research hypothesis is a statement that introduces a research question and proposes an expected result. It is an integral part of the scientific method that forms the basis of scientific experiments. Therefore, you need to be careful and thorough when building your research hypothesis. A minor flaw in the construction of your hypothesis could have an adverse effect on your experiment. In research, there is a convention that the hypothesis is written in two forms, the null hypothesis, and the alternative hypothesis (called the experimental hypothesis when the method of investigation is an experiment).

Characteristics of a Good Research Hypothesis

As the hypothesis is specific, there is a testable prediction about what you expect to happen in a study. You may consider drawing hypothesis from previously published research based on the theory.

A good research hypothesis involves more effort than just a guess. In particular, your hypothesis may begin with a question that could be further explored through background research.

To help you formulate a promising research hypothesis, you should ask yourself the following questions:

Is the language clear and focused?
What is the relationship between your hypothesis and your research topic?
Is your hypothesis testable? If yes, then how?
What are the possible explanations that you might want to explore?
Does your hypothesis include both an independent and dependent variable?
Can you manipulate your variables without hampering the ethical standards?
Does your research predict the relationship and outcome?
Is your research simple and concise (avoids wordiness)?
Is it clear with no ambiguity or assumptions about the readers’ knowledge
Is your research observable and testable results?
Is it relevant and specific to the research question or problem?

The questions listed above can be used as a checklist to make sure your hypothesis is based on a solid foundation. Furthermore, it can help you identify weaknesses in your hypothesis and revise it if necessary.

Source: Educational Hub

How to formulate a research hypothesis.

A testable hypothesis is not a simple statement. It is rather an intricate statement that needs to offer a clear introduction to a scientific experiment, its intentions, and the possible outcomes. However, there are some important things to consider when building a compelling hypothesis.

1. State the problem that you are trying to solve.

Make sure that the hypothesis clearly defines the topic and the focus of the experiment.

2. Try to write the hypothesis as an if-then statement.

Follow this template: If a specific action is taken, then a certain outcome is expected.

3. Define the variables

Independent variables are the ones that are manipulated, controlled, or changed. Independent variables are isolated from other factors of the study.

Dependent variables , as the name suggests are dependent on other factors of the study. They are influenced by the change in independent variable.

4. Scrutinize the hypothesis

Evaluate assumptions, predictions, and evidence rigorously to refine your understanding.

Types of Research Hypothesis

The types of research hypothesis are stated below:

1. Simple Hypothesis

It predicts the relationship between a single dependent variable and a single independent variable.

2. Complex Hypothesis

It predicts the relationship between two or more independent and dependent variables.

3. Directional Hypothesis

It specifies the expected direction to be followed to determine the relationship between variables and is derived from theory. Furthermore, it implies the researcher’s intellectual commitment to a particular outcome.

4. Non-directional Hypothesis

It does not predict the exact direction or nature of the relationship between the two variables. The non-directional hypothesis is used when there is no theory involved or when findings contradict previous research.

5. Associative and Causal Hypothesis

The associative hypothesis defines interdependency between variables. A change in one variable results in the change of the other variable. On the other hand, the causal hypothesis proposes an effect on the dependent due to manipulation of the independent variable.

6. Null Hypothesis

Null hypothesis states a negative statement to support the researcher’s findings that there is no relationship between two variables. There will be no changes in the dependent variable due the manipulation of the independent variable. Furthermore, it states results are due to chance and are not significant in terms of supporting the idea being investigated.

7. Alternative Hypothesis

It states that there is a relationship between the two variables of the study and that the results are significant to the research topic. An experimental hypothesis predicts what changes will take place in the dependent variable when the independent variable is manipulated. Also, it states that the results are not due to chance and that they are significant in terms of supporting the theory being investigated.

Research Hypothesis Examples of Independent and Dependent Variables

Research Hypothesis Example 1 The greater number of coal plants in a region (independent variable) increases water pollution (dependent variable). If you change the independent variable (building more coal factories), it will change the dependent variable (amount of water pollution).

Research Hypothesis Example 2 What is the effect of diet or regular soda (independent variable) on blood sugar levels (dependent variable)? If you change the independent variable (the type of soda you consume), it will change the dependent variable (blood sugar levels)

You should not ignore the importance of the above steps. The validity of your experiment and its results rely on a robust testable hypothesis. Developing a strong testable hypothesis has few advantages, it compels us to think intensely and specifically about the outcomes of a study. Consequently, it enables us to understand the implication of the question and the different variables involved in the study. Furthermore, it helps us to make precise predictions based on prior research. Hence, forming a hypothesis would be of great value to the research. Here are some good examples of testable hypotheses.

More importantly, you need to build a robust testable research hypothesis for your scientific experiments. A testable hypothesis is a hypothesis that can be proved or disproved as a result of experimentation.

Importance of a Testable Hypothesis

To devise and perform an experiment using scientific method, you need to make sure that your hypothesis is testable. To be considered testable, some essential criteria must be met:

There must be a possibility to prove that the hypothesis is true.
There must be a possibility to prove that the hypothesis is false.
The results of the hypothesis must be reproducible.

Without these criteria, the hypothesis and the results will be vague. As a result, the experiment will not prove or disprove anything significant.

What are your experiences with building hypotheses for scientific experiments? What challenges did you face? How did you overcome these challenges? Please share your thoughts with us in the comments section.

Frequently Asked Questions

The steps to write a research hypothesis are: 1. Stating the problem: Ensure that the hypothesis defines the research problem 2. Writing a hypothesis as an 'if-then' statement: Include the action and the expected outcome of your study by following a ‘if-then’ structure. 3. Defining the variables: Define the variables as Dependent or Independent based on their dependency to other factors. 4. Scrutinizing the hypothesis: Identify the type of your hypothesis

Hypothesis testing is a statistical tool which is used to make inferences about a population data to draw conclusions for a particular hypothesis.

Hypothesis in statistics is a formal statement about the nature of a population within a structured framework of a statistical model. It is used to test an existing hypothesis by studying a population.

Research hypothesis is a statement that introduces a research question and proposes an expected result. It forms the basis of scientific experiments.

The different types of hypothesis in research are: • Null hypothesis: Null hypothesis is a negative statement to support the researcher’s findings that there is no relationship between two variables. • Alternate hypothesis: Alternate hypothesis predicts the relationship between the two variables of the study. • Directional hypothesis: Directional hypothesis specifies the expected direction to be followed to determine the relationship between variables. • Non-directional hypothesis: Non-directional hypothesis does not predict the exact direction or nature of the relationship between the two variables. • Simple hypothesis: Simple hypothesis predicts the relationship between a single dependent variable and a single independent variable. • Complex hypothesis: Complex hypothesis predicts the relationship between two or more independent and dependent variables. • Associative and casual hypothesis: Associative and casual hypothesis predicts the relationship between two or more independent and dependent variables. • Empirical hypothesis: Empirical hypothesis can be tested via experiments and observation. • Statistical hypothesis: A statistical hypothesis utilizes statistical models to draw conclusions about broader populations.

Wow! You really simplified your explanation that even dummies would find it easy to comprehend. Thank you so much.

Thanks a lot for your valuable guidance.

I enjoy reading the post. Hypotheses are actually an intrinsic part in a study. It bridges the research question and the methodology of the study.

Useful piece!

This is awesome.Wow.

It very interesting to read the topic, can you guide me any specific example of hypothesis process establish throw the Demand and supply of the specific product in market

Nicely explained

It is really a useful for me Kindly give some examples of hypothesis

It was a well explained content ,can you please give me an example with the null and alternative hypothesis illustrated

clear and concise. thanks.

So Good so Amazing

Good to learn

Thanks a lot for explaining to my level of understanding

Explained well and in simple terms. Quick read! Thank you

It awesome. It has really positioned me in my research project

Rate this article Cancel Reply

Your email address will not be published.

Enago Academy's Most Popular Articles

Content Analysis vs Thematic Analysis: What's the difference?

Reporting Research

Choosing the Right Analytical Approach: Thematic analysis vs. content analysis for data interpretation

In research, choosing the right approach to understand data is crucial for deriving meaningful insights.…

Cross-sectional and Longitudinal Study Design

Comparing Cross Sectional and Longitudinal Studies: 5 steps for choosing the right approach

The process of choosing the right research design can put ourselves at the crossroads of…

Industry News

COPE Forum Discussion Highlights Challenges and Urges Clarity in Institutional Authorship Standards

The COPE forum discussion held in December 2023 initiated with a fundamental question — is…

Career Corner

Unlocking the Power of Networking in Academic Conferences

Embarking on your first academic conference experience? Fear not, we got you covered! Academic conferences…

Research Recommendations – Guiding policy-makers for evidence-based decision making

Research recommendations play a crucial role in guiding scholars and researchers toward fruitful avenues of…

Choosing the Right Analytical Approach: Thematic analysis vs. content analysis for…

Comparing Cross Sectional and Longitudinal Studies: 5 steps for choosing the right…

How to Design Effective Research Questionnaires for Robust Findings

Sign-up to read more

Subscribe for free to get unrestricted access to all our resources on research writing and academic publishing including:

2000+ blog articles
50+ Webinars
10+ Expert podcasts
50+ Infographics
10+ Checklists
Research Guides

We hate spam too. We promise to protect your privacy and never spam you.

I am looking for Editing/ Proofreading services for my manuscript Tentative date of next journal submission:

As a researcher, what do you consider most when choosing an image manipulation detector?

Choose Your Test

Sat / act prep online guides and tips, what is a hypothesis and how do i write one.

General Education

Think about something strange and unexplainable in your life. Maybe you get a headache right before it rains, or maybe you think your favorite sports team wins when you wear a certain color. If you wanted to see whether these are just coincidences or scientific fact, you would form a hypothesis, then create an experiment to see whether that hypothesis is true or not.

But what is a hypothesis, anyway? If you’re not sure about what a hypothesis is--or how to test for one!--you’re in the right place. This article will teach you everything you need to know about hypotheses, including:

Defining the term “hypothesis”
Providing hypothesis examples
Giving you tips for how to write your own hypothesis

So let’s get started!

What Is a Hypothesis?

Merriam Webster defines a hypothesis as “an assumption or concession made for the sake of argument.” In other words, a hypothesis is an educated guess . Scientists make a reasonable assumption--or a hypothesis--then design an experiment to test whether it’s true or not. Keep in mind that in science, a hypothesis should be testable. You have to be able to design an experiment that tests your hypothesis in order for it to be valid.

As you could assume from that statement, it’s easy to make a bad hypothesis. But when you’re holding an experiment, it’s even more important that your guesses be good...after all, you’re spending time (and maybe money!) to figure out more about your observation. That’s why we refer to a hypothesis as an educated guess--good hypotheses are based on existing data and research to make them as sound as possible.

Hypotheses are one part of what’s called the scientific method . Every (good) experiment or study is based in the scientific method. The scientific method gives order and structure to experiments and ensures that interference from scientists or outside influences does not skew the results. It’s important that you understand the concepts of the scientific method before holding your own experiment. Though it may vary among scientists, the scientific method is generally made up of six steps (in order):

Observation
Asking questions
Forming a hypothesis
Analyze the data
Communicate your results

You’ll notice that the hypothesis comes pretty early on when conducting an experiment. That’s because experiments work best when they’re trying to answer one specific question. And you can’t conduct an experiment until you know what you’re trying to prove!

Independent and Dependent Variables

After doing your research, you’re ready for another important step in forming your hypothesis: identifying variables. Variables are basically any factor that could influence the outcome of your experiment . Variables have to be measurable and related to the topic being studied.

There are two types of variables: independent variables and dependent variables. I ndependent variables remain constant . For example, age is an independent variable; it will stay the same, and researchers can look at different ages to see if it has an effect on the dependent variable.

Speaking of dependent variables... dependent variables are subject to the influence of the independent variable , meaning that they are not constant. Let’s say you want to test whether a person’s age affects how much sleep they need. In that case, the independent variable is age (like we mentioned above), and the dependent variable is how much sleep a person gets.

Variables will be crucial in writing your hypothesis. You need to be able to identify which variable is which, as both the independent and dependent variables will be written into your hypothesis. For instance, in a study about exercise, the independent variable might be the speed at which the respondents walk for thirty minutes, and the dependent variable would be their heart rate. In your study and in your hypothesis, you’re trying to understand the relationship between the two variables.

Elements of a Good Hypothesis

The best hypotheses start by asking the right questions . For instance, if you’ve observed that the grass is greener when it rains twice a week, you could ask what kind of grass it is, what elevation it’s at, and if the grass across the street responds to rain in the same way. Any of these questions could become the backbone of experiments to test why the grass gets greener when it rains fairly frequently.

As you’re asking more questions about your first observation, make sure you’re also making more observations . If it doesn’t rain for two weeks and the grass still looks green, that’s an important observation that could influence your hypothesis. You'll continue observing all throughout your experiment, but until the hypothesis is finalized, every observation should be noted.

Finally, you should consult secondary research before writing your hypothesis . Secondary research is comprised of results found and published by other people. You can usually find this information online or at your library. Additionally, m ake sure the research you find is credible and related to your topic. If you’re studying the correlation between rain and grass growth, it would help you to research rain patterns over the past twenty years for your county, published by a local agricultural association. You should also research the types of grass common in your area, the type of grass in your lawn, and whether anyone else has conducted experiments about your hypothesis. Also be sure you’re checking the quality of your research . Research done by a middle school student about what minerals can be found in rainwater would be less useful than an article published by a local university.

Writing Your Hypothesis

Once you’ve considered all of the factors above, you’re ready to start writing your hypothesis. Hypotheses usually take a certain form when they’re written out in a research report.

When you boil down your hypothesis statement, you are writing down your best guess and not the question at hand . This means that your statement should be written as if it is fact already, even though you are simply testing it.

The reason for this is that, after you have completed your study, you'll either accept or reject your if-then or your null hypothesis. All hypothesis testing examples should be measurable and able to be confirmed or denied. You cannot confirm a question, only a statement!

In fact, you come up with hypothesis examples all the time! For instance, when you guess on the outcome of a basketball game, you don’t say, “Will the Miami Heat beat the Boston Celtics?” but instead, “I think the Miami Heat will beat the Boston Celtics.” You state it as if it is already true, even if it turns out you’re wrong. You do the same thing when writing your hypothesis.

Additionally, keep in mind that hypotheses can range from very specific to very broad. These hypotheses can be specific, but if your hypothesis testing examples involve a broad range of causes and effects, your hypothesis can also be broad.

The Two Types of Hypotheses

Now that you understand what goes into a hypothesis, it’s time to look more closely at the two most common types of hypothesis: the if-then hypothesis and the null hypothesis.

#1: If-Then Hypotheses

First of all, if-then hypotheses typically follow this formula:

If ____ happens, then ____ will happen.

The goal of this type of hypothesis is to test the causal relationship between the independent and dependent variable. It’s fairly simple, and each hypothesis can vary in how detailed it can be. We create if-then hypotheses all the time with our daily predictions. Here are some examples of hypotheses that use an if-then structure from daily life:

If I get enough sleep, I’ll be able to get more work done tomorrow.
If the bus is on time, I can make it to my friend’s birthday party.
If I study every night this week, I’ll get a better grade on my exam.

In each of these situations, you’re making a guess on how an independent variable (sleep, time, or studying) will affect a dependent variable (the amount of work you can do, making it to a party on time, or getting better grades).

You may still be asking, “What is an example of a hypothesis used in scientific research?” Take one of the hypothesis examples from a real-world study on whether using technology before bed affects children’s sleep patterns. The hypothesis read s:

“We hypothesized that increased hours of tablet- and phone-based screen time at bedtime would be inversely correlated with sleep quality and child attention.”

It might not look like it, but this is an if-then statement. The researchers basically said, “If children have more screen usage at bedtime, then their quality of sleep and attention will be worse.” The sleep quality and attention are the dependent variables and the screen usage is the independent variable. (Usually, the independent variable comes after the “if” and the dependent variable comes after the “then,” as it is the independent variable that affects the dependent variable.) This is an excellent example of how flexible hypothesis statements can be, as long as the general idea of “if-then” and the independent and dependent variables are present.

#2: Null Hypotheses

Your if-then hypothesis is not the only one needed to complete a successful experiment, however. You also need a null hypothesis to test it against. In its most basic form, the null hypothesis is the opposite of your if-then hypothesis . When you write your null hypothesis, you are writing a hypothesis that suggests that your guess is not true, and that the independent and dependent variables have no relationship .

One null hypothesis for the cell phone and sleep study from the last section might say:

“If children have more screen usage at bedtime, their quality of sleep and attention will not be worse.”

In this case, this is a null hypothesis because it’s asking the opposite of the original thesis!

Conversely, if your if-then hypothesis suggests that your two variables have no relationship, then your null hypothesis would suggest that there is one. So, pretend that there is a study that is asking the question, “Does the amount of followers on Instagram influence how long people spend on the app?” The independent variable is the amount of followers, and the dependent variable is the time spent. But if you, as the researcher, don’t think there is a relationship between the number of followers and time spent, you might write an if-then hypothesis that reads:

“If people have many followers on Instagram, they will not spend more time on the app than people who have less.”

In this case, the if-then suggests there isn’t a relationship between the variables. In that case, one of the null hypothesis examples might say:

“If people have many followers on Instagram, they will spend more time on the app than people who have less.”

You then test both the if-then and the null hypothesis to gauge if there is a relationship between the variables, and if so, how much of a relationship.

4 Tips to Write the Best Hypothesis

If you’re going to take the time to hold an experiment, whether in school or by yourself, you’re also going to want to take the time to make sure your hypothesis is a good one. The best hypotheses have four major elements in common: plausibility, defined concepts, observability, and general explanation.

#1: Plausibility

At first glance, this quality of a hypothesis might seem obvious. When your hypothesis is plausible, that means it’s possible given what we know about science and general common sense. However, improbable hypotheses are more common than you might think.

Imagine you’re studying weight gain and television watching habits. If you hypothesize that people who watch more than twenty hours of television a week will gain two hundred pounds or more over the course of a year, this might be improbable (though it’s potentially possible). Consequently, c ommon sense can tell us the results of the study before the study even begins.

Improbable hypotheses generally go against science, as well. Take this hypothesis example:

“If a person smokes one cigarette a day, then they will have lungs just as healthy as the average person’s.”

This hypothesis is obviously untrue, as studies have shown again and again that cigarettes negatively affect lung health. You must be careful that your hypotheses do not reflect your own personal opinion more than they do scientifically-supported findings. This plausibility points to the necessity of research before the hypothesis is written to make sure that your hypothesis has not already been disproven.

#2: Defined Concepts

The more advanced you are in your studies, the more likely that the terms you’re using in your hypothesis are specific to a limited set of knowledge. One of the hypothesis testing examples might include the readability of printed text in newspapers, where you might use words like “kerning” and “x-height.” Unless your readers have a background in graphic design, it’s likely that they won’t know what you mean by these terms. Thus, it’s important to either write what they mean in the hypothesis itself or in the report before the hypothesis.

Here’s what we mean. Which of the following sentences makes more sense to the common person?

If the kerning is greater than average, more words will be read per minute.

If the space between letters is greater than average, more words will be read per minute.

For people reading your report that are not experts in typography, simply adding a few more words will be helpful in clarifying exactly what the experiment is all about. It’s always a good idea to make your research and findings as accessible as possible.

Good hypotheses ensure that you can observe the results.

#3: Observability

In order to measure the truth or falsity of your hypothesis, you must be able to see your variables and the way they interact. For instance, if your hypothesis is that the flight patterns of satellites affect the strength of certain television signals, yet you don’t have a telescope to view the satellites or a television to monitor the signal strength, you cannot properly observe your hypothesis and thus cannot continue your study.

Some variables may seem easy to observe, but if you do not have a system of measurement in place, you cannot observe your hypothesis properly. Here’s an example: if you’re experimenting on the effect of healthy food on overall happiness, but you don’t have a way to monitor and measure what “overall happiness” means, your results will not reflect the truth. Monitoring how often someone smiles for a whole day is not reasonably observable, but having the participants state how happy they feel on a scale of one to ten is more observable.

In writing your hypothesis, always keep in mind how you'll execute the experiment.

#4: Generalizability

Perhaps you’d like to study what color your best friend wears the most often by observing and documenting the colors she wears each day of the week. This might be fun information for her and you to know, but beyond you two, there aren’t many people who could benefit from this experiment. When you start an experiment, you should note how generalizable your findings may be if they are confirmed. Generalizability is basically how common a particular phenomenon is to other people’s everyday life.

Let’s say you’re asking a question about the health benefits of eating an apple for one day only, you need to realize that the experiment may be too specific to be helpful. It does not help to explain a phenomenon that many people experience. If you find yourself with too specific of a hypothesis, go back to asking the big question: what is it that you want to know, and what do you think will happen between your two variables?

Hypothesis Testing Examples

We know it can be hard to write a good hypothesis unless you’ve seen some good hypothesis examples. We’ve included four hypothesis examples based on some made-up experiments. Use these as templates or launch pads for coming up with your own hypotheses.

Experiment #1: Students Studying Outside (Writing a Hypothesis)

You are a student at PrepScholar University. When you walk around campus, you notice that, when the temperature is above 60 degrees, more students study in the quad. You want to know when your fellow students are more likely to study outside. With this information, how do you make the best hypothesis possible?

You must remember to make additional observations and do secondary research before writing your hypothesis. In doing so, you notice that no one studies outside when it’s 75 degrees and raining, so this should be included in your experiment. Also, studies done on the topic beforehand suggested that students are more likely to study in temperatures less than 85 degrees. With this in mind, you feel confident that you can identify your variables and write your hypotheses:

If-then: “If the temperature in Fahrenheit is less than 60 degrees, significantly fewer students will study outside.”

Null: “If the temperature in Fahrenheit is less than 60 degrees, the same number of students will study outside as when it is more than 60 degrees.”

These hypotheses are plausible, as the temperatures are reasonably within the bounds of what is possible. The number of people in the quad is also easily observable. It is also not a phenomenon specific to only one person or at one time, but instead can explain a phenomenon for a broader group of people.

To complete this experiment, you pick the month of October to observe the quad. Every day (except on the days where it’s raining)from 3 to 4 PM, when most classes have released for the day, you observe how many people are on the quad. You measure how many people come and how many leave. You also write down the temperature on the hour.

After writing down all of your observations and putting them on a graph, you find that the most students study on the quad when it is 70 degrees outside, and that the number of students drops a lot once the temperature reaches 60 degrees or below. In this case, your research report would state that you accept or “failed to reject” your first hypothesis with your findings.

Experiment #2: The Cupcake Store (Forming a Simple Experiment)

Let’s say that you work at a bakery. You specialize in cupcakes, and you make only two colors of frosting: yellow and purple. You want to know what kind of customers are more likely to buy what kind of cupcake, so you set up an experiment. Your independent variable is the customer’s gender, and the dependent variable is the color of the frosting. What is an example of a hypothesis that might answer the question of this study?

Here’s what your hypotheses might look like:

If-then: “If customers’ gender is female, then they will buy more yellow cupcakes than purple cupcakes.”

Null: “If customers’ gender is female, then they will be just as likely to buy purple cupcakes as yellow cupcakes.”

This is a pretty simple experiment! It passes the test of plausibility (there could easily be a difference), defined concepts (there’s nothing complicated about cupcakes!), observability (both color and gender can be easily observed), and general explanation ( this would potentially help you make better business decisions ).

Experiment #3: Backyard Bird Feeders (Integrating Multiple Variables and Rejecting the If-Then Hypothesis)

While watching your backyard bird feeder, you realized that different birds come on the days when you change the types of seeds. You decide that you want to see more cardinals in your backyard, so you decide to see what type of food they like the best and set up an experiment.

However, one morning, you notice that, while some cardinals are present, blue jays are eating out of your backyard feeder filled with millet. You decide that, of all of the other birds, you would like to see the blue jays the least. This means you'll have more than one variable in your hypothesis. Your new hypotheses might look like this:

If-then: “If sunflower seeds are placed in the bird feeders, then more cardinals will come than blue jays. If millet is placed in the bird feeders, then more blue jays will come than cardinals.”

Null: “If either sunflower seeds or millet are placed in the bird, equal numbers of cardinals and blue jays will come.”

Through simple observation, you actually find that cardinals come as often as blue jays when sunflower seeds or millet is in the bird feeder. In this case, you would reject your “if-then” hypothesis and “fail to reject” your null hypothesis . You cannot accept your first hypothesis, because it’s clearly not true. Instead you found that there was actually no relation between your different variables. Consequently, you would need to run more experiments with different variables to see if the new variables impact the results.

Experiment #4: In-Class Survey (Including an Alternative Hypothesis)

You’re about to give a speech in one of your classes about the importance of paying attention. You want to take this opportunity to test a hypothesis you’ve had for a while:

If-then: If students sit in the first two rows of the classroom, then they will listen better than students who do not.

Null: If students sit in the first two rows of the classroom, then they will not listen better or worse than students who do not.

You give your speech and then ask your teacher if you can hand out a short survey to the class. On the survey, you’ve included questions about some of the topics you talked about. When you get back the results, you’re surprised to see that not only do the students in the first two rows not pay better attention, but they also scored worse than students in other parts of the classroom! Here, both your if-then and your null hypotheses are not representative of your findings. What do you do?

This is when you reject both your if-then and null hypotheses and instead create an alternative hypothesis . This type of hypothesis is used in the rare circumstance that neither of your hypotheses is able to capture your findings . Now you can use what you’ve learned to draft new hypotheses and test again!

Key Takeaways: Hypothesis Writing

The more comfortable you become with writing hypotheses, the better they will become. The structure of hypotheses is flexible and may need to be changed depending on what topic you are studying. The most important thing to remember is the purpose of your hypothesis and the difference between the if-then and the null . From there, in forming your hypothesis, you should constantly be asking questions, making observations, doing secondary research, and considering your variables. After you have written your hypothesis, be sure to edit it so that it is plausible, clearly defined, observable, and helpful in explaining a general phenomenon.

Writing a hypothesis is something that everyone, from elementary school children competing in a science fair to professional scientists in a lab, needs to know how to do. Hypotheses are vital in experiments and in properly executing the scientific method . When done correctly, hypotheses will set up your studies for success and help you to understand the world a little better, one experiment at a time.

What’s Next?

If you’re studying for the science portion of the ACT, there’s definitely a lot you need to know. We’ve got the tools to help, though! Start by checking out our ultimate study guide for the ACT Science subject test. Once you read through that, be sure to download our recommended ACT Science practice tests , since they’re one of the most foolproof ways to improve your score. (And don’t forget to check out our expert guide book , too.)

If you love science and want to major in a scientific field, you should start preparing in high school . Here are the science classes you should take to set yourself up for success.

If you’re trying to think of science experiments you can do for class (or for a science fair!), here’s a list of 37 awesome science experiments you can do at home

Ashley Sufflé Robinson has a Ph.D. in 19th Century English Literature. As a content writer for PrepScholar, Ashley is passionate about giving college-bound students the in-depth information they need to get into the school of their dreams.

Ask a Question Below

Have any questions about this article or other topics? Ask below and we'll reply!

Improve With Our Famous Guides

For All Students

The 5 Strategies You Must Be Using to Improve 160+ SAT Points

How to Get a Perfect 1600, by a Perfect Scorer

Series: How to Get 800 on Each SAT Section:

Score 800 on SAT Math

Score 800 on SAT Reading

Score 800 on SAT Writing

Series: How to Get to 600 on Each SAT Section:

Score 600 on SAT Math

Score 600 on SAT Reading

Score 600 on SAT Writing

Free Complete Official SAT Practice Tests

What SAT Target Score Should You Be Aiming For?

15 Strategies to Improve Your SAT Essay

The 5 Strategies You Must Be Using to Improve 4+ ACT Points

How to Get a Perfect 36 ACT, by a Perfect Scorer

Series: How to Get 36 on Each ACT Section:

36 on ACT English

36 on ACT Math

36 on ACT Reading

36 on ACT Science

Series: How to Get to 24 on Each ACT Section:

24 on ACT English

24 on ACT Math

24 on ACT Reading

24 on ACT Science

What ACT target score should you be aiming for?

ACT Vocabulary You Must Know

ACT Writing: 15 Tips to Raise Your Essay Score

How to Get Into Harvard and the Ivy League

How to Get a Perfect 4.0 GPA

How to Write an Amazing College Essay

What Exactly Are Colleges Looking For?

Is the ACT easier than the SAT? A Comprehensive Guide

Should you retake your SAT or ACT?

When should you take the SAT or ACT?

Stay Informed

Get the latest articles and test prep tips!

Looking for Graduate School Test Prep?

Check out our top-rated graduate blogs here:

GRE Online Prep Blog

GMAT Online Prep Blog

TOEFL Online Prep Blog

Holly R. "I am absolutely overjoyed and cannot thank you enough for helping me!”

If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

To log in and use all the features of Khan Academy, please enable JavaScript in your browser.

Biology library

Course: biology library > unit 1, the scientific method.

Controlled experiments
The scientific method and experimental design

Introduction

Make an observation.
Ask a question.
Form a hypothesis , or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.

Scientific method example: Failure to toast

1. make an observation., 2. ask a question., 3. propose a hypothesis., 4. make predictions., 5. test the predictions..

If the toaster does toast, then the hypothesis is supported—likely correct.
If the toaster doesn't toast, then the hypothesis is not supported—likely wrong.

Logical possibility

Practical possibility, building a body of evidence, 6. iterate..

If the hypothesis was supported, we might do additional tests to confirm it, or revise it to be more specific. For instance, we might investigate why the outlet is broken.
If the hypothesis was not supported, we would come up with a new hypothesis. For instance, the next hypothesis might be that there's a broken wire in the toaster.

Want to join the conversation?

Upvote Button navigates to signup page
Downvote Button navigates to signup page
Flag Button navigates to signup page

Pavlov’s Dogs Experiment and Pavlovian Conditioning Response

Saul Mcleod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul Mcleod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

Learn about our Editorial Process

Olivia Guy-Evans, MSc

Associate Editor for Simply Psychology

BSc (Hons) Psychology, MSc Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

On This Page:

Like many great scientific advances, Pavlovian conditioning (aka classical conditioning) was discovered accidentally. Ivan Petrovich Pavlov (1849–1936) was a physiologist, not a psychologist.

During the 1890s, Pavlov researched salivation in dogs in response to being fed. He inserted a small test tube into the cheek of each dog to measure saliva when the dogs were fed (with a powder made from meat).

Pavlov predicted the dogs would salivate in response to the food in front of them, but he noticed that his dogs would begin to salivate whenever they heard the footsteps of his assistant, who was bringing them the food.

When Pavlov discovered that any object or event that the dogs learned to associate with food (such as the lab assistant) would trigger the same response, he realized that he had made an important scientific discovery.

Accordingly, he devoted the rest of his career to studying this type of learning.

Pavlovian Conditioning: Theory of Learning

Pavlov’s theory of learning, known as classical conditioning, or Pavlovian conditioning, posits that behaviors can be learned through the association between different stimuli.

Classical conditioning (later developed by Watson, in 1913) involves learning to associate an unconditioned stimulus that already brings about a particular response (i.e., a reflex) with a new (conditioned) stimulus, so that the new stimulus brings about the same response.

Pavlov developed some rather unfriendly technical terms to describe this process:

Neutral Stimulus (NS) : A stimulus that initially does not elicit a particular response or reflex action. In other words, before any conditioning takes place, the neutral stimulus has no effect on the behavior or physiological response of interest. For example, in Pavlov’s experiment, the sound of a metronome was a neutral stimulus initially, as it did not cause the dogs to salivate.
Unconditioned Stimulus (UCS): This is a stimulus that naturally and automatically triggers a response without any learning needed. In Pavlov’s experiment, the food was the unconditioned stimulus as it automatically induced salivation in the dogs.
Conditioned Stimulus (CS): This is a previously neutral stimulus that, after being repeatedly associated with an unconditioned stimulus, comes to trigger a conditioned response. For instance, in Pavlov’s experiment, the metronome became a conditioned stimulus when the dogs learned to associate it with food.
Conditioned Response (CR): This is a learned response to the conditioned stimulus. It typically resembles the unconditioned response but is triggered by the conditioned stimulus instead of the unconditioned stimulus. In Pavlov’s experiment, salivating in response to the metronome was the conditioned response.
Unconditioned Response (UR): This is an automatic, innate reaction to an unconditioned stimulus. It does not require any learning. In Pavlov’s experiment, the dogs’ automatic salivation in response to the food is an example of an unconditioned response.

Pavlov’s Dog Experiment

Pavlov (1902) started from the idea that there are some things that a dog does not need to learn. For example, dogs don’t learn to salivate whenever they see food. This reflex is ‘hard-wired’ into the dog.

Pavlov showed that dogs could be conditioned to salivate at the sound of a bell if that sound was repeatedly presented at the same time that they were given food.

Pavlov’s studies of classical conditioning have become famous since his early work between 1890 and 1930. Classical conditioning is “classical” in that it is the first systematic study of the basic laws of learning (also known as conditioning).

Pavlov’s dogs were individually situated in secluded environments, secured within harnesses. A food bowl was positioned before them, and a device was employed to gauge the frequency of their salivary gland secretions.

The data from these measurements were systematically recorded onto a rotating drum, allowing Pavlov to meticulously monitor the rates of salivation throughout the course of the experiments.

First, the dogs were presented with the food, and they salivated. The food was the unconditioned stimulus and salivation was an unconditioned (innate) response. (i.e., a stimulus-response connection that required no learning).

Unconditioned Stimulus (Food) > Unconditioned Response (Salivate)

In his experiment, Pavlov used a metronome as his neutral stimulus. By itself, the metronome did not elicit a response from the dogs.

Neutral Stimulus (Metronome) > No Response

Next, Pavlov began the conditioning procedure, whereby the clicking metronome was introduced just before he gave food to his dogs. After a number of repeats (trials) of this procedure, he presented the metronome on its own.

As you might expect, the sound of the clicking metronome on its own now caused an increase in salivation.

Conditioned Stimulus (Metronome) > Conditioned Response (Salivate)

So, the dog had learned an association between the metronome and the food, and a new behavior had been learned.

Because this response was learned (or conditioned), it is called a conditioned response (and also known as a Pavlovian response). The neutral stimulus has become a conditioned stimulus.

Temporal contiguity

Pavlov found that for associations to be made, the two stimuli had to be presented close together in time (such as a bell).

He called this the law of temporal contiguity. If the time between the conditioned stimulus (bell) and the unconditioned stimulus (food) is too great, then learning will not occur.

‘Unconditioning’ through experimental extinction

In extinction, the conditioned stimulus (the bell) is repeatedly presented without the unconditioned stimulus (the food).

Over time, the dog stops associating the sound of the bell with the food, and the conditioned response (salivation) weakens and eventually disappears.

In other words, the conditioned response is “unconditioned” or “extinguished.”

Spontaneous recovery

Pavlov noted the occurrence of “spontaneous recovery,” where the conditioned response can briefly reappear when the conditioned stimulus is presented after a rest period, even though the response has been extinguished.

This discovery added to the understanding of conditioning and extinction, indicating that these learned associations, while they can fade, are not completely forgotten.

Generalization

The principle of generalization suggests that after a subject has been conditioned to respond in a certain way to a specific stimulus, the subject will also respond in a similar manner to stimuli that are similar to the original one.

In Pavlov’s famous experiments with dogs, he found that after conditioning dogs to salivate at the sound of a bell (which was paired with food), the dogs would also salivate in response to similar sounds, like a buzzer.

This demonstrated the principle of generalization in classical conditioning.

However, the response tends to be more pronounced when the new stimulus closely resembles the original one used in conditioning.

This relationship between the similarity of the stimulus and the strength of the response is known as the generalization gradient.

This principle has been exemplified in research, including a study conducted by Meulders and colleagues in 2013.

Impact of Pavlov’s Research

Ivan Pavlov’s key contribution to psychology was the discovery of classical conditioning, demonstrating how learned associations between stimuli can influence behavior.

His work laid the foundation for behaviorism, influenced therapeutic techniques, and informed our understanding of learning and memory processes.

Behaviorism: Pavlov’s work laid the foundation for behaviorism , a major school of thought in psychology. The principles of classical conditioning have been used to explain a wide range of behaviors, from phobias to food aversions.

Therapy Techniques: Techniques based on classical conditioning, such as systematic desensitization and exposure therapy , have been developed to treat a variety of psychological disorders, including phobias and post-traumatic stress disorder (PTSD).

In these therapies, a conditioned response (such as fear) can be gradually “unlearned” by changing the association between a specific stimulus and its response.

Little Albert Experiment : The Little Albert experiment, conducted by John B. Watson in 1920, demonstrated that emotional responses could be classically conditioned in humans. A young child, “Little Albert,” was conditioned to fear a white rat, which generalized to similar objects.

Educational Strategies: Educational strategies, like repetitive learning and rote memorization, can be seen as applications of the principles of classical conditioning. The repeated association between stimulus and response can help to reinforce learning.

Marketing and Advertising: Principles from Pavlov’s conditioning experiments are often used in advertising to build brand recognition and positive associations.

For instance, a brand may pair its product with appealing stimuli (like enjoyable music or attractive visuals) to create a positive emotional response in consumers, who then associate the product with it.

Critical Evaluation

Pavlovian conditioning is traditionally described as learning an association between a neutral conditioned stimulus (CS) and an unconditioned stimulus (US), such that the CS comes to elicit a conditioned response (CR). This fits many lab studies but misses the adaptive function of conditioning (Domjan, 2005).

From a functional perspective, conditioning likely evolves to help organisms effectively interact with biologically important unconditioned stimuli (US) in their natural environment.

For conditioning to happen naturally, the conditioned stimulus (CS) can’t be arbitrary, but must have a real ecological relationship to the US as a precursor or feature of the US object.

Pavlovian conditioning prepares organisms for important biological events by conditioning compensatory responses that improve the organism’s ability to cope.

The critical behavior change from conditioning may not be conditioned responses (CRs), but rather conditioned modifications of unconditioned responses (URs) to the US that improve the organism’s interactions with it.

Evidence shows conditioning occurs readily with naturalistic CSs, like tastes before illness, infant cues before nursing, prey sights before attack. This conditioning is more robust and resistant to effects like blocking.

Traditional descriptions of Pavlovian conditioning as simply the acquired ability of one stimulus to evoke the original response to another stimulus paired with it are inadequate and misleading (Rescorla, 1988).

New research shows conditioning is actually about learning relationships between events, which allows organisms to build mental representations of their environment.

Just pairing stimuli together doesn’t necessarily cause conditioning. It depends on whether one stimulus gives information about the other.

Conditioning rapidly encodes relations among a broad range of stimuli, not just between a neutral stimulus and one eliciting a response. The learned associations allow complex representations of the world.

Recently, Honey et al. (2020, 2022) presented simulations using an alternative model called HeiDI that accounts for Rescorla’s findings. HeiDI differs by allowing reciprocal CS-US and US-CS associations. It uses consistent learning rules applied to all stimulus pairs.

The simulations suggest HeiDI explains Rescorla’s results via two mechanisms:

Changes in US-CS associations during compound conditioning, allowing greater change in some US-CS links
Indirect influences of CS-CS associations enabling compounds to recruit associative strength from absent stimuli

HeiDI integrates various conditioning phenomena and retains key Rescorla-Wagner insights about surprise driving learning. However, it moves beyond the limitations of Rescorla-Wagner by providing a framework to address how learning translates into performance.

HeiDI refers to the authors of the model (Honey, Dwyer, Iliescu) as well as highlighting a key feature of the model – the bidirectional or reciprocal associations it proposes between conditioned stimuli and unconditioned stimuli.

H – Honey (the lead author’s surname), ei – Bidirectional (referring to the reciprocal associations), D – Dwyer (the second author’s surname), I – Iliescu (the third author’s surname).

Domjan, M. (2005). Pavlovian conditioning: A functional perspective. Annu. Rev. Psychol. , 56 , 179-206.
Honey, R.C., Dwyer, D.M., & Iliescu, A.F. (2020a). HeiDI: A model for Pavlovian learning and performance with reciprocal associations. Psychological Review, 127, 829-852.
Honey, R. C., Dwyer, D. M., & Iliescu, A. F. (2022). Associative change in Pavlovian conditioning: A reappraisal . Journal of Experimental Psychology: Animal Learning and Cognition .
Meulders A, Vandebroek, N. Vervliet, B. and Vlaeyen, J.W.S. (2013). Generalization Gradients in Cued and Contextual Pain-Related Fear: An Experimental Study in Health Participants . Frontiers in Human Neuroscience , 7 (345). 1-12.
Pavlov, I. P. (1897/1902). The work of the digestive glands. London: Griffin.
Pavlov, I. P. (1928). Lectures on conditioned reflexes . (Translated by W.H. Gantt) London: Allen and Unwin.
Pavlov, I. P. (1927). Conditioned Reflexes: An Investigation of the Physiological Activity of the Cerebral Cortex . Translated and edited by Anrep, GV (Oxford University Press, London, 1927).
Rescorla, R. A. (1988). Pavlovian conditioning: It’s not what you think it is . American Psychologist , 43 (3), 151.
Pavlov, I. P. (1955). Selected works . Moscow: Foreign Languages Publishing House.
Watson, J.B. (1913). Psychology as the behaviorist Views It. Psychological Review, 20 , 158-177.
Watson, J. B., & Rayner, R. (1920). Conditioned emotional reactions. Journal of experimental psychology , 3 (1), 1.

What was the main point of Ivan Pavlov’s experiment with dogs?

The main point of Ivan Pavlov’s experiment with dogs was to study and demonstrate the concept of classical conditioning.

Pavlov showed that dogs could be conditioned to associate a neutral stimulus (such as a bell) with a reflexive response (such as salivation) by repeatedly pairing the two stimuli together.

This experiment highlighted the learning process through the association of stimuli and laid the foundation for understanding how behaviors can be modified through conditioning.

What is Pavlovian response?

The Pavlovian response, also known as a conditioned response, refers to a learned, automatic, and involuntary response elicited by a previously neutral stimulus through classical conditioning. It is a key concept in Pavlov’s experiments, where dogs learned to salivate in response to a bell.

When did Pavlov discover classical conditioning?

Ivan Pavlov discovered classical conditioning during his dog experiments in the late 1890s and early 1900s. His seminal work on classical conditioning, often called Pavlovian conditioning, laid the foundation for our understanding of associative learning and its role in behavior modification.

Soft Determinism In Psychology

Branches of Psychology

Social Action Theory (Weber): Definition & Examples

Adult Attachment , Personality , Psychology , Relationships

Attachment Styles and How They Affect Adult Relationships

Famous Experiments , Social Science

Solomon Asch Conformity Line Experiment Study

Learning Theories , Psychology , Social Science

Albert Bandura’s Social Learning Theory

Share full article

For more audio journalism and storytelling, download New York Times Audio , a new iOS app available for news subscribers.

Whales Have an Alphabet

Until the 1960s, it was uncertain whether whales made any sounds at all..

This transcript was created using speech recognition software. While it has been reviewed by human transcribers, it may contain errors. Please review the episode audio before quoting from this transcript and email [email protected] with any questions.

[MUSIC PLAYING]

From “The New York Times,” I’m Michael Barbaro. This is “The Daily.”

Today, ever since the discovery that whales produce songs, scientists have been trying to find a way to decipher their lyrics. After 60 years, they may have finally done it. My colleague, Carl Zimmer, explains.

It’s Friday, May 24.

I have to say, after many years of working with you on everything from the pandemic to —

— CRISPR DNA technology, that it turns out your interests are even more varied than I had thought, and they include whales.

They do indeed.

And why? What is it about the whale that captures your imagination?

I don’t think I’ve ever met anybody who is not fascinated by whales. I mean, these are mammals like us, and they’re swimming around in the water. They have brains that are much bigger than ours. They can live maybe 200 years. These are incredible animals, and animals that we still don’t really understand.

Right. Well, it is this majestic creature that brings us together today, Carl, because you have been reporting on a big breakthrough in our understanding of how it is that whales communicate. But I think in order for that breakthrough to make sense, I think we’re going to have to start with what we have known up until now about how whales interact. So tell us about that.

Well, people knew that whales and dolphins traveled together in groups, but up until the 1960s, we didn’t really know that whales actually made any sounds at all. It was actually sort of an accident that we came across it. The American military was developing sophisticated microphones to put underwater. They wanted to listen for Russian submarines.

As one does. But there was an engineer in Bermuda, and he started hearing some weird stuff.

[WHALE SOUNDS]

And he wondered maybe if he was actually listening to whales.

What made him wonder if it was whales, of all things?

Well, this sound did not sound like something geological.

It didn’t sound like some underwater landslide or something like that. This sounded like a living animal making some kind of call. It has these incredible deep tones that rise up into these strange, almost falsetto type notes.

It was incredibly loud. And so it would have to be some really big animal. And so with humpback whales swimming around Bermuda, this engineer thought, well, maybe these are humpback whales.

And so he gets in touch with a husband and wife team of whale biologists, Roger and Katy Payne, and plays these recordings to them. And they’re pretty convinced that they’re hearing whales, too. And then they go on to go out and confirm that by putting microphones in the water, chasing after groups of whales and confirming, yes, indeed, that these sounds are coming from these humpback whales.

So once these scientists confirm in their minds that these are the sounds of a whale, what happens with this discovery?

Well, Roger and Katy Payne and their colleagues are astonished that this species of whale is swimming around singing all the time for hours on end. And it’s so inspirational to them that they actually help to produce a record that they release “The Song of the Humpback Whale” in 1970.

And so this is being sold in record stores, you know, along with Jimi Hendrix and Rolling Stones. And it is a huge hit.

Yeah, it sells like two million copies.

Well, at the time, it was a huge cultural event. This record, this became almost like an anthem of the environmental movement. And it led, for whales in particular, to a lot of protections for them because now people could appreciate that whales were a lot more marvelous and mysterious than they maybe had appreciated before.

And so you have legislation, like the Marine Mammal Act. The United States just agrees just to stop killing whales. It stops its whaling industry. And so you could argue that the discovery of these whale songs in Bermuda led to at least some species of whales escaping extinction.

Well, beyond the cultural impact of this discovery, which is quite meaningful, I wonder whether scientists and marine biologists are figuring out what these whale songs are actually communicating.

So the Paynes create a whole branch of science, the study of whale songs. It turns out that pretty much every species of whale that we know of sings in some way or another. And it turns out that within a species, different groups of whales in different parts of the world may sing with a different dialect. But the big question of what these whales are singing, what do these songs mean, that remains elusive into the 21st century. And things don’t really change until scientists decide to take a new look at the problem in a new way.

And what is that new way?

So in 2020, a group of whale biologists, including Roger Payne, come together with computer scientists from MIT. Instead of humpback whales, which were the whales where whale songs are first discovered, these scientists decide to study sperm whales in the Caribbean. And humpback whales and sperm whales have very, very different songs. So if you’re used to humpback whales with their crazy high and low singing voices —

Right, those best-selling sounds.

— those are rockin’ tunes of the humpback whales, that’s not what sperm whales do. Sperm whales have a totally different way of communicating with each other. And I actually have some recordings that were provided by the scientists who have been doing this research. And so we can take a listen to some of them.

Wow, It’s like a rhythmic clicking.

These are a group of sperm whales swimming together, communicating.

So whale biologists knew already that there was some structure to this sound. Those clicks that you hear, they come in little pulses. And each of those pulses is known as a coda. And whale biologists had given names to these different codas. So, for example, they call one coda, one plus one plus three —

— which is basically click, click, click, click, click, or four plus three, where you have four clicks in a row and a pause and then three clicks in a row.

Right. And the question would seem to be, is this decipherable communication, or is this just whale gibberish?

Well, this is where the computer scientists were able to come in and to help out. The whale biologists who were listening to the codas from the sperm whales in the Caribbean, they had identified about 21 types. And then that would seem to be about it.

But then, an MIT computer science graduate student named Prajusha Sharma was given the job of listening to them again.

And what does she hear?

In a way, it’s not so much what she heard, but what she saw.

Because when scientists record whale songs, you can look at it kind of like if you’re looking at an audio of a recording of your podcast, you will see the little squiggles of your voice.

And so whale biologists would just look at that ticker of whale songs going across the screen and try to compare them. And Sharma said, I don’t like this. I just — this is not how I look at data. And so what she decided to do is she decided to kind of just visualize the data differently. And essentially, she just kind of flipped these images on their side and saw something totally new.

And what she saw was that sperm whales were singing a whole bunch of things that nobody had actually been hearing.

One thing that she discovered was that you could have a whale that was producing a coda over and over and over again, but it was actually playing with it. It was actually stretching out the coda,

[CLICKING] So to get a little bit longer and a little bit longer, a little bit longer.

And then get shorter and shorter and shorter again. They could play with their codas in a way that nobody knew before. And she also started to see that a whale might throw in an extra click at the end of a coda. So it would be repeating a coda over and over again and then boom, add an extra one right at the end. What they would call an ornamentation. So now, you have yet another signal that these whales are using.

And if we just look at what the sperm whales are capable of producing in terms of different codas, we go from just 21 types that they had found in the Caribbean before to 156. So what the scientists are saying is that what we might be looking at is what they call a sperm whale phonetic alphabet.

Yeah, that’s a pretty big deal because the only species that we know of for sure that has a phonetic alphabet —

— is us, exactly. So the reason that we can use language is because we can make a huge range of sounds by just doing little things with our mouths. A little change in our lips can change a bah to a dah. And so we are able to produce a set of phonetic sounds. And we put those sounds together to make words.

So now, we have sperm whales, which have at least 150 of these different versions of sounds that they make just by making little adjustments to the existing way that they make sounds. And so you can make a chart of their phonetic alphabet, just like you make a chart of the human phonetic alphabet.

So then, that raises the question, do they combine their phonetic alphabet into words? Do they combine their words into sentences? In other words, do sperm whales have a language of their own?

Right. Are they talking to each other, really talking to each other?

If we could really show that whales had language on par with humans, that would be like finding intelligent life on another planet.

We’ll be right back.

So, Carl, how should we think about this phonetic alphabet and whether sperm whales are actually using it to talk to each other?

The scientists on this project are really careful to say that these results do not definitively prove what these sperm whale sounds are. There are a handful of possibilities here in terms of what this study could mean. And one of them is that the whales really are using full-blown language.

What they might be talking about, we don’t know. I mean, perhaps they like to talk about their travels over hundreds and thousands of miles. Maybe they’re talking about, you know, the giant squid that they caught last night. Maybe they’re gossiping about each other.

And you have to remember, sperm whales are incredibly social animals. They have relationships that last for decades. And they live in groups that are in clans of thousands of whales. I mean, imagine the opportunities for gossip.

These are all at least imaginable now. But it’s also possible that they are communicating with each other, but in a way that isn’t language as we know it. You know, maybe these sounds that they’re producing don’t add up to sentences. There’s no verb there. There’s no noun. There’s no structure to it in terms of how we think of language.

But maybe they’re still conveying information to each other. Maybe they’re somehow giving out who they are and what group they belong to. But it’s not in the form of language that we think of.

Right. Maybe it’s more kind of caveman like as in whale to whale, look, there, food.

It’s possible. But, you know, other species have evolved in other directions. And so you have to put yourself in the place of a sperm whale. You know, so think about this. They are communicating in the water. And actually, like sending sounds through water is a completely different experience than through the air like we do.

So a sperm whale might be communicating to the whale right next to it a few yards away, but it might be communicating with whales miles away, hundreds of miles away. They’re in the dark a lot of the time, so they don’t even see the whales right next to them. So it’s just this constant sound that they’re making because they’re in this dark water.

So we might want to imagine that such a species would talk the way we do, but there are just so many reasons to expect that whatever they’re communicating might be just profoundly different, so different that it’s actually hard for us to imagine. And so we need to really, you know, let ourselves be open to lots of possibilities.

And one possibility that some scientists have raised is that maybe language is just the wrong model to think about. Maybe we need to think about music. You know, maybe this strange typewriter, clickety clack is actually not like a Morse code message, but is actually a real song. It’s a kind of music that doesn’t necessarily convey information the way conversation does, but it brings the whales together.

In humans, like, when we humans sing together in choruses, it can be a very emotional experience. It’s a socially bonding experience, but it’s not really like the specific words that we’re singing that bring us together when we’re singing. It’s sharing the music together.

But at a certain point, we stop singing in the chorus, and we start asking each other questions like, hey, what are you doing for dinner? How are you going to get home? There’s a lot of traffic on the BQE. So we are really drawn to the possibility that whales are communicating in that same kind of a mode.

We’re exchanging information. We’re seeking out each other’s well-being and emotional state. And we’re building something together.

And I think that happens because, I mean, language is so fundamental to us as human beings. I mean, it’s like every moment of our waking life depends on language. We are talking to ourselves if we’re not talking to other people.

In our sleep, we dream, and there are words in our dreams. And we’re just stewing in language. And so it’s really, really hard for us to understand how other species might have a really complex communication system with hundreds of different little units of sound that they can use and they can deploy. And to think anything other than, well, they must be talking about traffic on the BQE. Like —

— we’re very human-centric. And we have to resist that.

So what we end up having here is a genuine breakthrough in our understanding of how whales interact. And that seems worth celebrating in and of itself. But it really kind of doubles as a lesson in humility for us humans when it comes to appreciating the idea that there are lots of non-human ways in which language can exist.

That’s right. Humility is always a good idea when we’re thinking about other animals.

So what now happens in this realm of research? And how is it that these scientists, these marine biologists and these computer scientists are going to try to figure out what exactly this alphabet amounts to and how it’s being used?

So what’s going to happen now is a real sea change in gathering data from whales.

So to speak.

So these scientists are now deploying a new generation of undersea microphones. They’re using drones to follow these whales. And what they want to do is they want to be recording sounds from the ocean where these whales live 24 hours a day, seven days a week. And so the hope is that instead of getting, say, a few 100 codas each year on recording, these scientists want to get several hundred million every year, maybe billions of codas every year.

And once you get that much data from whales, then you can start to do some really amazing stuff with artificial intelligence. So these scientists hope that they can use the same kind of artificial intelligence that is behind things like ChatGPT or these artificial intelligence systems that are able to take recordings of people talking and transcribing them into text. They want to use that on the whale communication.

They want to just grind through vast amounts of data, and maybe they will discover more phonetic letters in this alphabet. Who knows? Maybe they will actually find bigger structures, structures that could correspond to language.

If you go really far down this route of possibilities, the hope is that you would understand what sperm whales are saying to each other so well that you could actually create artificial sperm whale communication, and you could play it underwater. You could talk to the sperm whales. And they would talk back. They would react somehow in a way that you had predicted. If that happens, then maybe, indeed, sperm whales have something like language as we understand it.

And the only way we’re going to figure that out is if we figure out not just how they talk to themselves, but how we can perhaps talk to them, which, given everything we’ve been talking about here, Carl, is a little bit ironic because it’s pretty human-centric.

That’s right. This experiment could fail. It’s possible that sperm whales don’t do anything like language as we know it. Maybe they’re doing something that we can’t even imagine yet. But if sperm whales really are using codas in something like language, we are going to have to enter the conversation to really understand it.

Well, Carl, thank you very much. We appreciate it.

Thank you. Sorry. Can I say that again? My voice got really high all of a sudden.

A little bit like a whale’s. Ooh.

Yeah, exactly. Woot. Woot.

Thank yoooo. No. Thank you.

Here’s what else you need to know today.

We allege that Live Nation has illegally monopolized markets across the live concert industry in the United States for far too long. It is time to break it up.

On Thursday, the Justice Department sued the concert giant Live Nation Entertainment, which owns Ticketmaster, for violating federal antitrust laws and sought to break up the $23 billion conglomerate. During a news conference, Attorney General Merrick Garland said that Live Nation’s monopolistic tactics had hurt the entire industry of live events.

The result is that fans pay more in fees, artists have fewer opportunities to play concerts, smaller promoters get squeezed out, and venues have fewer real choices.

In a statement, Live Nation called the lawsuit baseless and vowed to fight it in court.

A reminder — tomorrow, we’ll be sharing the latest episode of our colleagues’ new show, “The Interview.” This week on “The Interview,” Lulu Garcia-Navarro talks with Ted Sarandos, the CEO of Netflix, about his plans to make the world’s largest streaming service even bigger.

I don’t agree with the premise that quantity and quality are somehow in conflict with each other. I think our content and our movie programming has been great, but it’s just not all for you.

Today’s episode was produced by Alex Stern, Stella Tan, Sydney Harper, and Nina Feldman. It was edited by MJ Davis, contains original music by Pat McCusker, Dan Powell, Elisheba Ittoop, Marion Lozano, and Sophia Lanman, and was engineered by Alyssa Moxley. Our theme music is by Jim Brunberg and Ben Landsverk of Wonderly.

Special thanks to Project SETI for sharing their whale recordings.

That’s it for “The Daily.” I’m Michael Barbaro. See you on Tuesday after the holiday.

May 31, 2024 • 31:29 Guilty
May 30, 2024 • 25:21 The Government Takes On Ticketmaster
May 29, 2024 • 29:46 The Closing Arguments in the Trump Trial
May 28, 2024 • 25:56 The Alitos and Their Flags
May 24, 2024 • 25:18 Whales Have an Alphabet
May 23, 2024 • 34:24 I.C.C. Prosecutor Requests Warrants for Israeli and Hamas Leaders
May 22, 2024 • 23:20 Biden’s Open War on Hidden Fees
May 21, 2024 • 24:14 The Crypto Comeback
May 20, 2024 • 31:51 Was the 401(k) a Mistake?
May 19, 2024 • 33:23 The Sunday Read: ‘Why Did This Guy Put a Song About Me on Spotify?’
May 17, 2024 • 51:10 The Campus Protesters Explain Themselves
May 16, 2024 • 30:47 The Make-or-Break Testimony of Michael Cohen

Hosted by Michael Barbaro

Featuring Carl Zimmer

Produced by Alex Stern , Stella Tan , Sydney Harper and Nina Feldman

Edited by MJ Davis Lin

Original music by Elisheba Ittoop , Dan Powell , Marion Lozano , Sophia Lanman and Pat McCusker

Engineered by Alyssa Moxley

Listen and follow The Daily Apple Podcasts | Spotify | Amazon Music | YouTube

Ever since the discovery of whale songs almost 60 years ago, scientists have been trying to decipher the lyrics.

But sperm whales don’t produce the eerie melodies sung by humpback whales, sounds that became a sensation in the 1960s. Instead, sperm whales rattle off clicks that sound like a cross between Morse code and a creaking door. Carl Zimmer, a science reporter, explains why it’s possible that the whales are communicating in a complex language.

On today’s episode

Carl Zimmer , a science reporter for The New York Times who also writes the Origins column .

A diver, who appears minuscule, swims between a large sperm whale and her cub in blue waters.

Background reading

Scientists find an “alphabet” in whale songs.

These whales still use their vocal cords. But how?

There are a lot of ways to listen to The Daily. Here’s how.

We aim to make transcripts available the next workday after an episode’s publication. You can find them at the top of the page.

The Daily is made by Rachel Quester, Lynsea Garrison, Clare Toeniskoetter, Paige Cowett, Michael Simon Johnson, Brad Fisher, Chris Wood, Jessica Cheung, Stella Tan, Alexandra Leigh Young, Lisa Chow, Eric Krupke, Marc Georges, Luke Vander Ploeg, M.J. Davis Lin, Dan Powell, Sydney Harper, Mike Benoist, Liz O. Baylen, Asthaa Chaturvedi, Rachelle Bonja, Diana Nguyen, Marion Lozano, Corey Schreppel, Rob Szypko, Elisheba Ittoop, Mooj Zadie, Patricia Willens, Rowan Niemisto, Jody Becker, Rikki Novetsky, John Ketchum, Nina Feldman, Will Reid, Carlos Prieto, Ben Calhoun, Susan Lee, Lexie Diao, Mary Wilson, Alex Stern, Dan Farrell, Sophia Lanman, Shannon Lin, Diane Wong, Devon Taylor, Alyssa Moxley, Summer Thomad, Olivia Natt, Daniel Ramirez and Brendan Klinkenberg.

Our theme music is by Jim Brunberg and Ben Landsverk of Wonderly. Special thanks to Sam Dolnick, Paula Szuchman, Lisa Tobin, Larissa Anderson, Julia Simon, Sofia Milan, Mahima Chablani, Elizabeth Davis-Moorer, Jeffrey Miranda, Renan Borelli, Maddy Masiello, Isabella Anderson and Nina Lassam.

Carl Zimmer covers news about science for The Times and writes the Origins column . More about Carl Zimmer

All Human Existence May Have Begun in a Black Hole, Some Scientists Believe

There’s an intriguing possibility that the emergence of conscious life is not just a coincidence, but an inevitable outcome of cosmic evolution.

So let’s contemplate something simpler: why does the universe allow us to exist? Yet again, we run into the same problem: if the universe didn’t allow us to exist, we wouldn’t be here to think about it. This is called the “anthropic principle.” For some, it’s the only answer we need to explain, well , everything; but for others, it’s a philosophical thorn in the side. Everything we know about the universe so far—dating back to the 16th-century Polish astronomer Copernicus, who first proposed that Earth travels around the sun rather than the other way around—tells us that we have no special place in the cosmos. We are not at the center. This is the “Copernican principle.”

.css-2l0eat{font-family:UnitedSans,UnitedSans-roboto,UnitedSans-local,Helvetica,Arial,Sans-serif;font-size:1.625rem;line-height:1.2;margin:0rem;padding:0.9rem 1rem 1rem;}@media(max-width: 48rem){.css-2l0eat{font-size:1.75rem;line-height:1;}}@media(min-width: 48rem){.css-2l0eat{font-size:1.875rem;line-height:1;}}@media(min-width: 64rem){.css-2l0eat{font-size:2.25rem;line-height:1;}}.css-2l0eat b,.css-2l0eat strong{font-family:inherit;font-weight:bold;}.css-2l0eat em,.css-2l0eat i{font-style:italic;font-family:inherit;} Why do we exist as self-aware beings, tiny in size and minuscule in lifespan, relative to the lonely cosmic vastness mostly devoid of life?

The anthropic and Copernican principles are conflicting axioms about the universe’s existence and our place within it. The anthropic principle says the universe depends on our being here. Meanwhile, the Copernican principle says that we are not special, and no law of physics should depend on our existence. Yet, the vast and ancient universe we see in our telescopes appears to balance both principles, like a pin balanced on the edge of a glass.

So why is our universe the way it is, and why do we exist as self-aware beings , tiny in size and minuscule in lifespan, relative to the lonely cosmic vastness mostly devoid of life? If the universe were made just for us, surely it would be small, human sized, perhaps just one planet or solar system or galaxy, not billions. Why should a universe made for us have black holes, for example? They seem to contribute nothing to our welfare.

Some scientists believe the universe wasn’t finely tuned to create intelligent life like us at all. Instead, they say, the universe evolved its own insurance policy by creating as many black holes as possible, which is the universe’s method of reproduction. Following this line of thinking, the universe itself may very well be alive—and the fact that we humans exist at all is just a happy side effect.

A Finely-Tuned Universe

One of the biggest philosophical problems with the universe is that it has to be finely tuned for us to even exist. If the universe were random, things would quickly become messy. If modified only a tiny bit one way or another, physical parameters such as the speed of light ; the mass of the electron, proton, and neutron ; the gravitational constant ; and so on would eliminate all life—possibly all matter itself—and even the universe as a whole would not last long enough to evolve anything. For example, if their masses were slightly different, protons would decay into neutrons instead of the other way around, and as a result, there would be no atoms.

One possible solution to fine tuning is the multiverse . In this speculative theory, our universe is one of many in the same way that the planet Earth is one of many planets. Different universes have different laws of physics and, therefore, that ours supports life is simply a matter of luck. While some theories of the multiverse propose that these universes are essentially random and have no relationship to one another, one particular multiverse theory suggests that universes in fact reproduce like living beings and have ancestors and descendants. This theory is called cosmological natural selection (or CNS for short). First proposed by theoretical physicist Lee Smolin in 1992, the CNS theory is a strong contender for why our universe seems to balance both the Anthropic and Copernican principles.

When we look at the complexity of living things and the sheer number of non-living configurations there are, we’re left to assume that there’s no way species could appear randomly. Hence, some powerful being must have created all types of living creatures individually as a watchmaker builds a watch, the thinking often goes. However, Charles Darwin’s theory of evolution, which he first posited in his 1859 book, On the Origin of Species, provides a mechanism that explains why living things are non-random. Their parameters are not freely chosen; they are the product of natural selection , the process by which members of a species that are better fit to survive and/or reproduce more effectively are more likely to pass on their genes.

The theory of evolution is one of the greatest success stories in the history of science because it provided a mechanism by which a thing that is highly ordered, complex, and finely tuned for its survival could arise from natural processes. The theory was successful not only because it explained how species arise, but also because it generated new predictions that we could then test. For example, the theory of evolution explains why species appear related to one another.

The Beauty in Black Holes

The cosmological natural selection theory solves the pernicious problem of a universe finely tuned for life. That idea may make sense to us, living on a planet full of complex, multicellular organisms, but Earth is surrounded by mostly dead space and, as far as we know, dead planets, and moons and light years of interstellar dust and stray photons.

Earth is finely tuned for life; the universe is not. However, the cosmological natural selection theory says that the universe is finely tuned for something else: its method of reproduction, giving birth to new universes.

Under the CNS theory framework, every black hole becomes a baby universe . Our universe, likewise, started out as a black hole in its mother universe. The theory says that inside every black hole, the central singularity—which is matter highly compressed in space in the mother universe—becomes a highly compressed point in time in the new universe. This point expands, creating new matter and energy. You get a complete universe from even a tiny black hole .

This means that our universe is finely tuned not for life, but for black holes, which typically come from massive stars (although they can have other origins). It turns out that massive star formation depends on an element also important for life on Earth: carbon.

Carbon monoxide is the second-most common molecule in the universe after molecular hydrogen, even more common than water. In the molecular clouds of gas and dust that form from supernovae, massive stars coalesce amid gaseous carbon monoxide molecules, which act as a coolant. This cooling helps matter clump together and form the stars. Carbon is a critical component in all life that we know of. Therefore, life is, in fact, a byproduct of stellar formation, which is itself a byproduct of what the universe evolved to do: create as many black holes as possible.

The cosmological natural selection theory helps explain why our universe is so highly ordered, complex, and self-sustaining like Darwin’s theory explains the same for living things. That leads to the tantalizing, if speculative, conclusion that perhaps, by some definition, our universe itself is alive.

Dr. Tim Andersen is a principal research scientist at Georgia Tech Research Institute. He earned his doctorate in mathematics from Rensselaer Polytechnic Institute in Troy, New York, and his undergraduate degree from the University of Texas at Austin. He has published academic works in statistical mechanics, fluid dynamics (including a monograph on vortex filaments), quantum field theory, and general relativity. He is the author of The Infinite Universe on Medium and Stubstack and a book by the same name. He lives with his wife and two cats, and has a son and daughter at home as well as one grown son.

preview for Popular Mechanics All Sections

.css-cuqpxl:before{padding-right:0.3125rem;content:'//';display:inline;} Pop Mech Pro: Science .css-xtujxj:before{padding-left:0.3125rem;content:'//';display:inline;}

Dark Matter Could Unlock a Limitless Energy Source

a frozen human brain inside a spinning ice cube 3d illustration

Could Freezing Your Brain Help You Live Forever?

The CIA’s Secret Plan to Use Mind Control

The Universe Could Be Eternal, This Theory Says

human hands stretched out to the burning sun, ethereal and unreal concepts of universe, spiritual and natural powers otherwise, fires burning down the past life, natural disaster, climate change and global warming, inferno, hell and chaos ultimate conceptual shot

Immortality Is Impossible Until We Beat Physics

How Vacuum Energy Could Help Us Reach Light Speed

Could the Chair You Sit on Have a Soul?

conceptual image of skyscrapers made of trees

Here’s How We Could Live in Trees

The Engine Driving Our Oceans Could Die by 2100

numbers around a phantom face in black and blue

Can AI Help Solve Math’s Thorniest Mysteries?

You Can Give Your Body Back to Nature When You Die

Professor Brian Cox Shut Down Flat Earth Theory With Simple Response, And It Was Awesome.

W e're all adults here, right? We know that the Flat Earth theory isn't correct…right? Despite overwhelming scientific evidence ; photographs of our planet from space, scientific experiments, military math used in World Wars , a small but vocal group continues to advocate for a flat Earth. This group includes figures like former boxer Carl Froch, who insists the Earth is flat and dismisses any real imagery as "cartoons ". 1 However, their arguments found no sympathy from physicist Professor Brian Cox, who effectively dismantled the Flat Earth theory with a simple and straightforward answer.

The Question That Sparked It All

A few years ago, Professor Brian Cox was fielding questions from the public on various scientific topics when someone asked him about the Flat Earth theory. This question set the stage for one of the most definitive rejections ever that the Earth is flat. Cox, known for his approachable demeanor and clear communication style, did not mince words. He said, "There is absolutely no basis at all for thinking the world is flat. Nobody in human history, as far as I know, has thought the world was flat".

Read More: NASA Discovered a Potentially Habitable Planet – An Alternative To Mars?

Historical Context and Scientific Evidence

Now, it's worth noting that there indeed have been people in history who believed the Earth was flat. There were concerns of sailing off the edge of the world (as depicted in Pirates of the Caribbean) but these concerns were addressed hundreds of years ago. Ancient civilizations like the Greeks had already measured the Earth's radius thousands of years ago. "The Greeks measured the radius of the Earth. I cannot conceive of a reason why anybody would think the world is flat", he remarked. The fact that Flat Earth Theory has come back around and persists now is worrisome.

Visual Proof from Space

As well as historical evidence, Cox highlighted modern proof too. Photographs of Earth taken from space show a round planet, making the flat Earth notion even more ridiculous. Cox expressed his disdain for Flat Earth Theory despite such clear evidence. " The very simple fact we've taken pictures of it. I'm lost for words, it's probably the most nonsensical suggestion that a thinking human being could possibly make. It is drivel" , he stated bluntly.

Why You Need to Be Putting 2 tbsp of Apple Cider Vinegar in Your Water Bottle Every Morning

Read More: Scientists have just discovered Earth's twin planet – and there might be something living on it

The Impact of Cox's Response

Cox's emphatic dismissal of the Flat Earth theory was not just defending scientific truth but also an attempt to call to reason and critical thinking. By addressing the question head-on and providing clear, scientifically-backed answers, he tried to educate and hopefully persuade some Flat Earthers to reconsider their opinion. His response was rooted in empirical evidence and scientific reasoning, which is something we hope those who adhere to Flat Earth Theory can learn to do as well.

The Aftermath and Continuing Debate

Despite Cox's clear answer, the Flat Earth theory persists today. Some former believers have been swayed by the ability to observe the Earth's curvature firsthand, but their has been slower than you'd think. But we cannot blame these individuals for sticking to their laurels. Us "globeheads," welcome these new additions with open arms.

Professor Brian Cox's proper dismantling of the Flat Earth theory is as simple as providing proof and logic. He effectively shut down one of the most persistent pseudoscientific beliefs by saying "just look". The importance of education and critical thinking cannot be understated here, as well as combating misinformation to foster a better understanding of our world.

H/t: Lad Bible

Read More: If a ‘Planet Killer' Astroid is Going to Hit Earth, This is How NASA Will Warn The World

The post Professor Brian Cox Shut Down Flat Earth Theory With Simple Response, And It Was Awesome. appeared first on The Hearty Soul .

10 Skin Conditions That Could Be Signs of Heart Disease

@drlesliedobson/TikTok jetcityimage/Adobe Stock (Licensed)

‘You can judge me all you want’: Trader Joe’s customer says you shouldn’t return shopping carts

'i will grab your cart and put directly behind your car.'.

Brooke Sjoberg

Posted on May 31, 2024 Updated on May 31, 2024, 1:40 pm CDT

In the sphere of social media, even the most innocuous statements can quickly draw the ire of a large group of people.

Frequently, discussions around politics and even practices like tipping can turn incendiary, as people often have strong, differing opinions about these topics.

One that might have flown under the radar as being controversial for many is returning your shopping cart at the grocery store .

One Trader Joe’s shopper called out other customers who give her dirty looks for not taking her shopping cart back to the cart return located in the parking lot. In her TikTok, @drlesliedobson a psychologist and content creator, says she refuses to leave her children alone in her car long enough to return her shopping cart.

“I’m not returning my shopping cart and you can judge me all you want,” she says in the video. “I’m not getting my groceries into my car, getting my children into the car and then leaving them in the car to go return the cart. So if you’re going to give me a dirty look, f*ck off.”

The Daily Dot has reached out to @drlesliedobson via TikTok direct message regarding the video.

@drlesliedobson #groceryshopping #shoppingcart #traderjoes #protectourchildren #protectourkids #educational #groceries #singlemom #drleslie ♬ original sound – Dr. Leslie

What is the ‘shopping cart theory?’

Some folks have determined that a person’s attitude toward returning their shopping cart after a trip to the store can say a lot about them. Described as the “shopping cart theory,” it is essentially a social litmus test that gauges an individual’s moral character. As previously reported by the Daily Dot , it proposes that a person’s capacity to manage themselves can be determined by whether they choose to return their shopping cart to its proper place or abandon it once it’s served its purpose.

However, shopping carts have been known to present some issues for shoppers who park in shared lots, especially if they are equipped with wheel locks tied to a geolocation system that only allows them to roll freely within a certain radius. Customers who have parked farther than these boundaries allow carts to travel have reported that they either have to leave their groceries long enough to move their car or remove their groceries from the cart altogether .

The video was met with harsh criticism from viewers who strongly disagreed with the poster about her personal shopping cart return policy.

“I have seen carts roll into parked cars just from the wind pushing them so no matter what, I always try to return them,” one commenter wrote. “I don’t want my car banged into, I won’t do it to others inadvertently.”

“One thing I’ve noticed after moving to America recently is that shopping cart return stations are all over the parking lot so never really more than 20 seconds away and you still can’t be bothered?” another said.

“My sister has 5 kids and still puts her cart in the corral,” one commented. “If you’re too lazy to put a cart up, that you got out, then do pick up instead.”

However, other commenters revealed that the poster is not alone in her opinion that there are times when they would rather not return their cart.

“I have the worst trouble with this at Costco,” one commenter wrote. “The return things are ROWS away. I’m not leaving my baby in the car where I can’t see it.”

“All the people saying ‘I always park by the cart corral’ are missing the point at places like Aldi that makes you take the cart back to the front of the building,” another wrote.

“I’ve thought the same thing,” one said. “Even by myself, walking way down away from my car to the cart corral is dangerous these days. I wouldn’t dare if my children with still little either. I’m with you on this.”

The internet is chaotic—but we’ll break it down for you in one daily email. Sign up for the Daily Dot’s web_crawlr newsletter here to get the best (and worst) of the internet straight into your inbox.

Brooke Sjoberg is a freelance writer for the Daily Dot. She graduated with her Bachelors in Journalism from the University of Texas at Austin in 2020.

Danica Patrick backs Joe Rogan, divisive U.S. conspiracy theory

Updated: May. 30, 2024, 3:40 p.m. |
Published: May. 30, 2024, 10:48 a.m.

Race driver Danica Patrick walks out of the pit area with her car after she qualified on the first day of qualifications for the Indianapolis 500 auto race at the Indianapolis Motor Speedway in Indianapolis, Saturday, May 10, 2008. Patrick qualified with a speed of 225.197 mph. (AP Photo/Tom Strattman) AP

Todderick Hunt | NJ Advance Media for NJ.com

Just because one partakes in the most American sport doesn’t mean that they side with the country on all issues. Former Indy Car and Nascar driver Danica Patrick , 42, continues to prove just that as she backed her latest conspiracy theory on Wednesday via X, formerly known as Twitter.

Here’s how things played out, courtesy of Chris Rosvoglou of TheSpun.com:

MORE SPORTS COVERAGE

Alabama vs. Duke FREE LIVE STREAM (5/31/24): Watch Women’s College World Series 2024 online | Time, TV, channel
New York Mets vs. Arizona Diamondbacks FREE LIVE STREAM (5/31/24): Watch MLB game online | Time, TV, channel
Strikeout-prone, Ex-Yankees prospect DFA’d by Guardians
Picks, previews for 2024 boys lacrosse semifinal playoff matchups
Ex-Jets receiver is ready for ‘explosive’ year

If you purchase a product or register for an account through a link on our site, we may receive compensation. By using this site, you consent to our User Agreement and agree that your clicks, interactions, and personal information may be collected, recorded, and/or stored by us and social media and other third-party partners in accordance with our Privacy Policy.

IMAGES

13 Different Types of Hypothesis (2024)
How to Write a Hypothesis in 12 Steps 2024
🏷️ Formulation of hypothesis in research. How to Write a Strong
2. What is your hypothesis (or hypotheses) for this experiment? ( acids
PPT
Hypothesis

VIDEO

What Is A Hypothesis?
Deduction|Hypotheses| Experiment| Results and conclusion| lecture 3
Proportion Hypothesis Testing, example 2
Writing Research Questions and Hypothesis Statements
Writing a hypothesis
WHAT IS A HYPOTHESIS ?

COMMENTS

How to Write a Strong Hypothesis
4. Refine your hypothesis. You need to make sure your hypothesis is specific and testable. There are various ways of phrasing a hypothesis, but all the terms you use should have clear definitions, and the hypothesis should contain: The relevant variables; The specific group being studied; The predicted outcome of the experiment or analysis; 5.
Hypothesis: Definition, Examples, and Types
A hypothesis is a tentative statement about the relationship between two or more variables. It is a specific, testable prediction about what you expect to happen in a study. It is a preliminary answer to your question that helps guide the research process. Consider a study designed to examine the relationship between sleep deprivation and test ...
What is a Hypothesis
Definition: Hypothesis is an educated guess or proposed explanation for a phenomenon, based on some initial observations or data. It is a tentative statement that can be tested and potentially proven or disproven through further investigation and experimentation. Hypothesis is often used in scientific research to guide the design of experiments ...
Experiments and Hypotheses
This would qualify as an experiment because the scientist is now making a change in the system and observing the effects. Forming a Hypothesis. When conducting scientific experiments, researchers develop hypotheses to guide experimental design. A hypothesis is a suggested explanation that is both testable and falsifiable.
Hypothesis Testing
Step 5: Present your findings. The results of hypothesis testing will be presented in the results and discussion sections of your research paper, dissertation or thesis.. In the results section you should give a brief summary of the data and a summary of the results of your statistical test (for example, the estimated difference between group means and associated p-value).
Research Hypothesis: Definition, Types, Examples and Quick Tips
3. Simple hypothesis. A simple hypothesis is a statement made to reflect the relation between exactly two variables. One independent and one dependent. Consider the example, "Smoking is a prominent cause of lung cancer." The dependent variable, lung cancer, is dependent on the independent variable, smoking. 4.
4.14: Experiments and Hypotheses
Experiments and further observations are often used to test the hypotheses. A scientific experiment is a carefully organized procedure in which the scientist intervenes in a system to change something, then observes the result of the change. Scientific inquiry often involves doing experiments, though not always.
Writing a Hypothesis for Your Science Fair Project
A hypothesis is a tentative, testable answer to a scientific question. Once a scientist has a scientific question she is interested in, the scientist reads up to find out what is already known on the topic. Then she uses that information to form a tentative answer to her scientific question. Sometimes people refer to the tentative answer as "an ...
Writing a Hypothesis for Your Science Fair Project
A hypothesis is the best answer to a question based on what is known. Scientists take that best answer and do experiments to see if it still makes sense or if a better answer can be made. When a scientist has a question they want to answer, they research what is already known about the topic. Then, they come up with their best answer to the ...
Subject Guides: Scientific Method: Step 3: HYPOTHESIS
Now it's time to state your hypothesis. The hypothesis is an educated guess as to what will happen during your experiment. The hypothesis is often written using the words "IF" and "THEN." For example, "If I do not study, then I will fail the test." The "if' and "then" statements reflect your independent and dependent variables.
What Is a Hypothesis? The Scientific Method
A hypothesis (plural hypotheses) is a proposed explanation for an observation. The definition depends on the subject. In science, a hypothesis is part of the scientific method. It is a prediction or explanation that is tested by an experiment. Observations and experiments may disprove a scientific hypothesis, but can never entirely prove one.
What is a Research Hypothesis and How to Write a Hypothesis
The steps to write a research hypothesis are: 1. Stating the problem: Ensure that the hypothesis defines the research problem. 2. Writing a hypothesis as an 'if-then' statement: Include the action and the expected outcome of your study by following a 'if-then' structure. 3.
Research Hypothesis In Psychology: Types, & Examples
A research hypothesis, in its plural form "hypotheses," is a specific, testable prediction about the anticipated results of a study, established at its outset. It is a key component of the scientific method. Hypotheses connect theory to data and guide the research process towards expanding scientific understanding.
Guide to Experimental Design
Table of contents. Step 1: Define your variables. Step 2: Write your hypothesis. Step 3: Design your experimental treatments. Step 4: Assign your subjects to treatment groups. Step 5: Measure your dependent variable. Other interesting articles. Frequently asked questions about experiments.
How to Formulate a Hypothesis for an Experiment
Steps for Formulating a Hypothesis for an Experiment. Step 1: State the question your experiment is looking to answer. Step 2: Identify your independent and dependant variables. Step 3: Write an ...
Controlled experiments (article)
Some types of hypotheses can't be tested in controlled experiments for ethical or practical reasons. For example, a hypothesis about viral infection can't be tested by dividing healthy people into two groups and infecting one group: infecting healthy people would not be safe or ethical.
Experimental Hypothesis
A hypothesis is an important first step to designing and carrying out experiments. Hypotheses often have three main parts, one part that explains what will happen in the experiment, another part ...
Scientific hypothesis
Countless hypotheses have been developed and tested throughout the history of science.Several examples include the idea that living organisms develop from nonliving matter, which formed the basis of spontaneous generation, a hypothesis that ultimately was disproved (first in 1668, with the experiments of Italian physician Francesco Redi, and later in 1859, with the experiments of French ...
What Is a Hypothesis and How Do I Write One?
Hypotheses are one part of what's called the scientific method . Every (good) experiment or study is based in the scientific method. The scientific method gives order and structure to experiments and ensures that interference from scientists or outside influences does not skew the results.
The scientific method (article)
The scientific method. At the core of biology and other sciences lies a problem-solving approach called the scientific method. The scientific method has five basic steps, plus one feedback step: Make an observation. Ask a question. Form a hypothesis, or testable explanation. Make a prediction based on the hypothesis.
Steps of the Scientific Method
The six steps of the scientific method include: 1) asking a question about something you observe, 2) doing background research to learn what is already known about the topic, 3) constructing a hypothesis, 4) experimenting to test the hypothesis, 5) analyzing the data from the experiment and drawing conclusions, and 6) communicating the results ...
Writing a hypothesis and prediction
A hypothesis is an idea about how something works that can be tested using experiments. A prediction says what will happen in an experiment if the hypothesis is correct. Presenter 1: We are going ...
Pavlov's Dogs Experiment & Pavlovian Conditioning Response
Pavlov's theory of learning, known as classical conditioning, or Pavlovian conditioning, posits that behaviors can be learned through the association between different stimuli. ... For example, in Pavlov's experiment, the sound of a metronome was a neutral stimulus initially, as it did not cause the dogs to salivate. Unconditioned Stimulus ...
Whales Have an Alphabet
This experiment could fail. It's possible that sperm whales don't do anything like language as we know it. Maybe they're doing something that we can't even imagine yet. But if sperm whales ...
How 'Cosmological Natural Selection' Could Explain Your Very Existence
The cosmological natural selection theory helps explain why our universe is so highly ordered, complex, and self-sustaining like Darwin's theory explains the same for living things. That leads ...
Sunning Your Butthole and Other 'Fun' Conspiracy Theories: What People
The theory comes from German author Heribert Illig who detailed the theory in a 1996 (sorry, I mean 1699) book. Illig lays the blame for the missing time on Holy Roman Emperor Otto III and Pope ...
Professor Brian Cox Shut Down Flat Earth Theory With Simple ...
Professor Brian Cox's proper dismantling of the Flat Earth theory is as simple as providing proof and logic. He effectively shut down one of the most persistent pseudoscientific beliefs by saying ...
Did This Trader Joe's Customer Fail the 'Shopping Cart Theory?'
Some folks have determined that a person's attitude toward returning their shopping cart after a trip to the store can say a lot about them. Described as the "shopping cart theory," it is ...
Danica Patrick backs Joe Rogan, divisive U.S. conspiracy theory
Published: May. 30, 2024, 10:48 a.m. Race driver Danica Patrick walks out of the pit area with her car after she qualified on the first day of qualifications for the Indianapolis 500 auto race at ...

How to Write a Great Hypothesis

Hypothesis Format

Hypothesis Types

At a Glance

The Hypothesis in the Scientific Method

Elements of a Good Hypothesis

How to Formulate a Good Hypothesis

The Importance of Operational Definitions

Replicability

Hypothesis Checklist

A few examples of simple hypotheses:

Examples of a complex hypothesis include:

Examples of a null hypothesis include:

Examples of an alternative hypothesis:

Collecting Data on Your Hypothesis

Descriptive Research Methods

Experimental Research Methods

What is a Hypothesis – Types, Examples and Writing Guide

Types of Hypothesis

Research Hypothesis

Null Hypothesis

Alternative Hypothesis

Directional Hypothesis

Non-directional Hypothesis

Statistical Hypothesis

Composite Hypothesis

Empirical Hypothesis

Simple Hypothesis

Complex Hypothesis

Applications of Hypothesis

How to write a Hypothesis

Identify the Research Question

Conduct a Literature Review

Determine the Variables

Formulate the Hypothesis

Write the Null Hypothesis

Refine the Hypothesis

Examples of Hypothesis

Purpose of Hypothesis

When to use Hypothesis

Characteristics of Hypothesis

Advantages of Hypothesis

Limitations of Hypothesis

About the author

Muhammad Hassan

You may also like

Data Collection – Methods Types and Examples

Delimitations in Research – Types, Examples and...

Research Process – Steps, Examples and Tips

Research Design – Types, Methods and Examples

Institutional Review Board – Application Sample...

Evaluating Research – Process, Examples and...

Module 1: Introduction to Biology

Forming a Hypothesis

Practice Questions

Testing a Vaccine

Practice Question

Experimental Design

Experimental Variables

Margin Size

4.14: Experiments and Hypotheses

Forming a Hypothesis

Practice Questions

Testing a Vaccine

Practice Question

Experimental Design

Experimental Variables

Contributors and Attributions

Scientific Method: Step 3: HYPOTHESIS

Step 3: State your hypothesis

Resource Links

What Is a Hypothesis? (Science)

Writing a Hypothesis

Null Hypothesis and Alternative Hypothesis

Example of a Hypothesis

How to Develop a Good Research Hypothesis

What is Hypothesis?

What is a Research Hypothesis?

Characteristics of a Good Research Hypothesis

Source: Educational Hub