critical legal research methodology

critical legal theory

Primary tabs.

Critical legal studies (CLS) is a theory which states that the law is necessarily intertwined with social issues, particularly stating that the law has inherent social biases . Proponents of CLS believe that the law supports the interests of those who create the law. As such, CLS states that the law supports a power dynamic which favors the historically privileged and disadvantages the historically underprivileged. CLS finds that the wealthy and the powerful use the law as an instrument for oppression to maintain their place in hierarchy. Many in the CLS movement want to overturn the hierarchical structures of modern society and they focus on the law as a tool in achieving this goal.

CLS was officially started in 1977 at the conference at the University of Wisconsin-Madison, but its roots extend earlier to when many of its founding members participated in social activism surrounding the Civil Rights movement and the Vietnam War. The founders of CLS borrowed from non-legal fields such as social theory, political philosophy, economics, and literary theory. Among noted CLS theorists are Roberto Mangabeira Unger, Robert W. Gordon, and Duncan Kennedy. 

Although CLS has been largely contained within the United States, it was influenced to a great extent by European philosophers, such as Karl Marx, Max Weber, Max Horkheimer, Antonio Gramsci, and Michel Foucault. CLS has borrowed heavily from  Legal Realism , the school of legal thought that flourished in the 1920s and 1930s. Like CLS scholars, legal realists rebelled against accepted legal theories of the day and urged the legal field to pay more attention to the social context of the law.

CLS includes several subgroups with fundamentally different, even contradictory, views.  Feminist legal theory  examines the role of gender in the law.  Critical race theory (CRT)  examines the role of race in the law.  Postmodernism  is a critique of the law influenced by developments in literary theory, and it emphasizes political economy and the economic context of legal decisions and issues.

An Introduction to “Critical Legal Research: The Next Wave”

Ronald E. Wheeler Online Symposium: “Critical Legal Research: The Next Wave” (A Panel in Honor of Richard Delgado and Jean Stefancic) 101 B.U. L. Rev. Online 1 (2021) PDF

This symposium continues and sustains the exchange of ideas initiated at a panel presentation offered at the 2021 American Association of Law Schools (“AALS”) Annual Meeting in January 2021. The panel was titled Critical Legal Research: The Next Wave , [1] and here we advance and extend that conversation with written contributions from the panelists.

The symposium and panel are outgrowths of truly organic collaboration that sprang from the passion for critical legal research felt by both the panel’s honorees—Professors Richard Delgado and Jean Stefancic—and an exceptional group of academic law librarian scholars—Yasmin Sokkar Harker, Julie Krishnaswami, Grace Lo, Nicholas Mignanelli, and Nicholas F. Stump. Indeed their passion for Critical Race Theory and its potential impact on the law—and also, necessarily, on legal research—has stood the test of time by maintaining its power and its appeal to all those who struggle against the oppressive forces that permeate and sustain our economic and social order. Thirty years after Delgado and Stefancic first exposed these radical ideas to the light of day, the torch has been passed to a new generation of lawyers, legal academics, law librarians, and scholars.

BIOGRAPHICAL INTRODUCTION

I want to begin with a very personal story in the tradition of the honorees of the Critical Legal Research: The Next Wave panel discussion. The year is 1987, and the location is Ann Arbor, Michigan. After receiving my Bachelor of Arts in Accounting, I moved from my family home in Detroit to Ann Arbor to attend the University of Michigan Law School. Me! The black, gay man with the “Artist Formerly Known as Prince” haircut that cascaded downward over one of my eyes. Admittedly, I had quite a look.

Yet, I was ready to be inspired; to be intellectually challenged; to discover ways of interpreting and applying the law that made sense; to learn legal tools that I could apply to my experiences growing up in Detroit, to those of my automotive-worker father and my clerical-worker mother, or to those of my grandparents, one a custodial worker and the other a chauffeur.

What I found was that nothing in law school seemed relevant to my life experiences. Indeed, everything in and outside of classes served to erase, invalidate, ignore, or dismiss all that I knew was real and truthful, even if ugly or oppressive. Black students told me, “You’re not Black . . . you’re gay!” Gay students told me, “You’re TOO out, don’t speak to us in the hallways.” I was on the verge of dropping out and leaving law school altogether.

Yet, I did return for my second year, and that year I took a course called Black Legal Scholarship taught by Professor Culp who was visiting that year from Howard University School of Law. In that class, we read Patricia Williams, and her words were transcendent. Suddenly, I felt less crazy. I felt SEEN. Finally, a legal scholar speaking the truth; my truth. From Patricia Williams, I moved on to Derrick Bell, Mari Matsuda, and the panel’s honorees Richard Delgado and Jean Stefancic. Fast forward thirty-four years, and here I am today with those early Crits [2] —Williams, Bell, Matsuda, Delgado, and Stefancic—continuing to influence my understanding of the law and its impact on everything and everyone.

So, quite literally, I owe my legal career to the panel’s honorees. If I were to call them my saviors, I would, in no way, be overstating the impact that Richard Delgado, Jean Stefancic, and their contemporaries—those legal scholars that spawned what was then called Critical Legal Studies—have had on my life.

INTRODUCTION OF RICHARD DELGADO AND JEAN STEFANCIC

So, I just want to say out loud that it is a bit of a setup for me to be given the task of introducing our honorees, these two fearless, profound, inspired, inspiring, thinkers, storytellers, scholars, visionaries, AND two people whom I count among my personal saviors. Yet here we are.

Professor Jean Stefancic is a Professor and Clement Research Affiliate at the University of Alabama School of Law, where she writes about civil rights, law reform, social change, and legal scholarship. She has written and co-authored over fifty articles and fifteen books, many with her husband Richard Delgado, with whom she shared writing residencies in Italy. Their book, Critical White Studies: Looking Behind the Mirror , [3] won a Gustavus Myers Outstanding Book Award, and How Lawyers Lose Their Way , [4] examines how law practice can stifle creativity. Before the University of Alabama, Stefancic taught at Seattle University School of Law, the University of Pittsburgh School of Law, and the University of Colorado Law School. During her five years at the University of Pittsburgh, she was a Research Professor of Law and a Derrick Bell Scholar, and while at the University of Colorado, she was affiliated with the Latino/a Research & Policy Center and served on the advisory committee of the Center of the American West.

Professor Richard Delgado teaches civil rights and Critical Race Theory at the University of Alabama School of Law where he holds the John J. Sparkman Chair of Law. Earlier, he taught at the University of Pittsburgh, the University of Colorado, and UCLA. He has written and co-authored numerous articles and books, many with his wife Jean Stefancic. He is a founder of the Critical Race Theory school of legal scholarship, and is also notable for his scholarship on hate speech and for introducing storytelling into legal scholarship. Delgado has authored more than 200 journal articles and twenty books, and his work has been praised or reviewed in The Nation , the New Republic , the New York Times , the Washington Post , and the Wall Street Journal . His books have won eight national book prizes, including six Gustavus Myers awards for an outstanding book on human rights in North America, the American Library Association’s Outstanding Academic Book, and a Pulitzer Prize nomination. Professor Delgado’s teaching and writing focus on race, the legal profession, and social change.

SUBJECT MATTER INTRODUCTION

Let me now briefly frame the discussion in this symposium with a few facts.

For those who may be unfamiliar with Critical Race Theory, I offer the following definition. The Critical Race Theory (“CRT”) movement is a collection of activists and scholars engaged in studying and transforming the relationship among race, racism, and power. The movement considers many of the same issues that conventional civil rights and ethnic studies discourses take up but places them in a broader perspective that includes economics, history, setting, group and self-interest, and emotions and the unconscious. CRT questions the very foundations of the liberal order, including equality theory, legal reasoning, Enlightenment rationalism, and neutral principles of constitutional law. [5] Important scholars contributing to the theory include Patricia Williams, Derrick Bell, Richard Delgado, Kimberlé Williams Crenshaw, and Mari Matsuda.

What is the “triple helix dilemma” in legal research? In 1989, Delgado and Stefancic’s article, “ Why Do We Tell the Same Stories?: Law Reform, Critical Librarianship, and the Triple Helix Dilemma ,” appeared in the Stanford Law Review . [6] The article described how the major classification systems most widely used to engage in legal research—the Lib rary of Congress subject heading system, the Index to Legal Periodicals , and the West Digest System—all function as hegemonic forces that serve to reinforce the status quo and to impede any meaningful change. [7] It explained how these classification systems replicate preexisting ideas, thoughts, and approaches necessarily and by design. [8] By doing so the article posited that they stifle creativity and original thought, they obscure nuances, and they ensure that oppressive forces within the law are strengthened by rendering evolution or changes nearly impossible. [9]

In 2007, Delgado and Stefancic’s article, “ Why Do We Ask the Same Questions? The Triple Helix Dilemma Revisited ,” appeared in Law Library Journal . [10] In this article, they exposed how computer-assisted legal research and electronic searching pose many of the same constraints and merit many of the same criticisms attributed to their print predecessors. [11] Moreover, this later article pointed out that computers, the hoped-for savior from hegemony, only delivered more of the same. [12]

Oddly and wonderfully, in an all-things-come-full-circle sort of way, in 2011, I wrote the article, “Does WestlawNext Really Change Everything? The Implications of WestlawNext on Legal Research.” [13] In that article I critiqued what we now know as artificial intelligence and machine learning as applied to research algorithms like the one employed in WestlawNext. [14] I made many observations about WestlawNext which are similar or the same as those offered by Delgado and Stefancic.

INTRODUCTION OF THE SYMPOSIUM OF LAW LIBRARIANS

Our exciting symposium consists of professional academic law librarians all of whom are emerging critical information scholars. In the symposium, they offer their reflections on how Delgado and Stefancic’s “triple helix dilemma” has shaped their thinking and continues to be relevant to their writing and teaching. In addition, Delgado and Stefancic offer reflections on legal research through the eyes of their fictional character, Rodrigo Crenshaw. [15]

Nicholas F. Stump, “Non-Reformist Reforms” in Radical Social Change: A Critical Legal Research Exploration , 101 B.U. L. Rev. Online 6 (2021).

Yasmin Sokkar Harker, Invisible Hands and the Triple (Quadruple?) Helix Dilemma: Helping Students Free Their Minds , 101 B.U. L. Rev. Online 17 (2021).

Grace Lo, Biases in Law Library Subject Headings , 101 B.U. L. Rev. Online 26 (2021).

Julie Graves Krishnaswami, Using Principles of Critical Information Theory to Teach Progressive Approaches to Regulatory Research , 101 B.U. L. Rev. Online 38 (2021).

Nicholas Mignanelli, Prophets for an Algorithmic Age , 101 B.U. L. Rev. Online 41 (2021).

Richard Delgado & Jean Stefancic, Rodrigo’s Reappraisal , 101 B.U. L. Rev. Online 48 (2021).

[1] AALS Open Source Program , Ass’n Am. L. Schs., https://memberaccess.aals.org /eweb/DynamicPage.aspx?webcode=SesDetails&ses_key=c00d4e33-ef02-4409-b610-af5b65258b9b [https://perma.cc/QVA5-2X23] (last visited Mar. 30, 2021).

[2] See Kimberlé Williams Crenshaw, Twenty Years of Critical Race Theory: Looking Back to Move Forward , 43 Conn. L. Rev. 1253, 1287-95 (2011), for an historical account of early Race Crits, and Mark Tushnet, Critical Legal Studies: A Political History , 100 Yale L.J. 1515 (1991), for an historical account of the Critical Legal Studies movement.

[3] Critical White Studies: Looking Behind the Mirror (Richard Delgado & Jean Stefancic eds., 1997).

[4] Jean Stefancic & Richard Delgado, How Lawyers Lose Their Way: A Profession Fails Its Creative Minds (2005).

[5] See generally Richard Delgado & Jean Stefancic, Critical Race Theory: An Introduction (3d ed. 2017).

[6] Richard Delgado & Jean Stefancic, Why Do We Tell the Same Stories?: Law Reform, Critical Librarianship, and the Triple Helix Dilemma , 42 Stan. L. Rev. 207 (1989).

[7] Id. at 209-16.

[8] Id. at 216-22.

[9] Id. at 222.

[10] Richard Delgado & Jean Stefancic, Why Do We Ask the Same Questions? The Triple Helix Dilemma Revisited , 99 Law Libr. J. 307 (2007).

[11] Id. at 317-24.

[12] Id. at 324-28.

[13] Ronald E. Wheeler, Does WestlawNext Really Change Everything? The Implications of WestlawNext on Legal Research , 103 Law Libr. J. 359 (2011).

[14] Id. at 364-77.

[15] See Richard Delgado, Rodrigo’s Chronicle , 101 Yale L.J. 1357 (1992) (book review), for the first installment in their long-running “Rodrigo” series.

Share this:

• Share on Facebook (Opens in new window)
• Click to share on Twitter (Opens in new window)
• Click to share on Reddit (Opens in new window)
• Click to share on LinkedIn (Opens in new window)
• Click to share on Pocket (Opens in new window)

Critical Legal Theory

• About This Guide
• Introductions to Legal Theory
• Methodology
• Books & Articles
• Journals about Social Justice
• Journals about Gender Inequality
• Journals about Race
• Critical Judgments
• Journals about Theory
• Legal Citation This link opens in a new window

About this Guide

This is a guide for researchers interested in researching critical legal theory, specifically critical legal studies, feminist legal theory, and critical race theory. These theoretical approaches react against and build on the work of classic legal theory which is described in its own research guide.

As an introduction to legal theory this guide lists encyclopedias for brief overviews of legal theory and general overview books. It also includes methodology resources including Sage Research Methods, which is a central reference resource, and handbooks.

This guide then goes into more detail about three specific topics: critical legal studies , feminist legal theory , and critical race theory . Each has a brief definition and a list of key resources, including relevant books that provide an introduction to the topic, methodological overview, history, or scholarly application. There are also lists of journals focusing on social justice , gender inequity , race , and general theory , many of which overlap in scope. Searching within specific journals by title is a narrow approach, so researchers can also refer to article resources for relevant legal databases. 

This guide also contains resources related to critical judgments , which are rewritten legal judgments from a specific critical perspective.

For information about critical disability theory and queer legal theory see the Lakehead Guide on Critical Legal Theories . This guide also includes lists of relevant podcasts.

Book a Research Help Appointment

Research help is available for students, faculty, and staff of TMU with legal research questions.

For one-on-one assistance in refining a legal research topic, finding legal information, and using databases and other resources, book a research appointment. Currently, all Law Library research help appointments are being conducted virtually through Zoom. Email the law librarians or book a time directly in their calendars during office hours: John Papadopoulos is available at [email protected] , with bookable office hours Lisa Levesque is available at [email protected] , with bookable office hours Sara Klein is available at [email protected] , with bookable office hours

Email : for general inquiries, please email  [email protected]  for assistance with accessing or using legal information resources and one of the Law Library staff will respond to you.

For the most recent service information during COVID-19, see the updates for students , instructors , and researchers .

Creative Commons License

This guide has been created by the Toronto Metropolitan University Library and is licensed under a Creative Commons Attribution International 4.0 License unless otherwise marked.

Guide Last Updated

Date Updated: August 16th, 2023

• Next: Introductions to Legal Theory >>
• Last Updated: Aug 23, 2024 11:00 AM
• URL: https://learn.library.torontomu.ca/criticallegaltheory

The Research Method: Law Reform Design

• First Online: 18 October 2019

Cite this chapter

• Kristina Loguinova 4  

Part of the book series: Economic and Financial Law & Policy – Shifting Insights & Values ((EFLP,volume 4))

331 Accesses

Due to the criticism of Critical Legal Studies coming down to nothing more than nihilism, the third chapter of the first part of this monograph identifies law reform design as the most appropriate research method for answering research questions from a Critical Legal Studies’ perspective. Namely, law reform design provides for the opportunity to formulate constructive solutions instead of engaging in critique for the sake of critique. Also, this chapter suggest to make a distinction between a micro and macro design of law reform.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Subscribe and save.

• Get 10 units per month
• Download Article/Chapter or eBook
• 1 Unit = 1 Article or 1 Chapter
• Cancel anytime
• Available as PDF
• Read on any device
• Instant download
• Own it forever
• Available as EPUB and PDF
• Compact, lightweight edition
• Dispatched in 3 to 5 business days
• Free shipping worldwide - see info
• Durable hardcover edition

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Gordon ( 1998 ), p. 87; Williams ( 2011 ), p. 374; Williams (1987), pp. 431–496; Caudill ( 1987 ), pp. 292–292; Kelman ( 1987 ), p. 9; Rabinowitz (1998), p. 681; Hutchinson and Monahan ( 1984 ), p. 236; Schlag (2009), p. 298; Gabel ( 2009 ), p. 519. To set the tone for the following chapter it seems appropriate to quote Freeman on the nihilist allegation. “The goal of trashing, however, is not liberation into nihilist resignation. I am no nihilist. If anything, I might be more justly accused of having utopian tendencies. The point of delegitimation is to expose possibilities more truly expressing reality, possibilities of fashioning a future that might at least partially realize a substantive notion of justice instead of the abstract, rightsy, traditional, bourgeois notions of justice that generate so much of the contradictory scholarship.”: Freeman ( 1981 ), p. 1230.

Hunt ( 1987 ), p. 7. A similar point has been made by Schwartz: Schwartz ( 1984 ), p. 422.

Russell ( 1986 ), p. 3.

Fischl ( 1992 ), pp. 783–805. Indeed, by solely trashing ( unfreezing the world as it now appears) a Crit engages in a liberating and creating activity to encourage imagination and innovation. That is, not a completely worthless and useless activity per se: Hutchinson ( 1989 ), p. 8; Hutchinson and Monahan ( 1984 ), pp. 227–228. Crits are in other words not obsessed with normative questions in concern to what to do next (a form of neurotic projection): Fischl ( 1992 ), pp. 783–805.

Gordon ( 1998 ), p. 83.

Gordon ( 1998 ), p. 83 (personally added underlineation). Zamboni has also spoken encouragingly of Crits engaging in concrete project of reconstruction after they finish with trashing. Namely, “[o]nce free from the traditional formalistic legal barriers erected between the law and politics, CLS legal scholar should then not be indifferent to the type of [ideology] the legal order ought to implement in society. In other words, she should primarily charge her investigation with political indications of the type of [ideology] the law-making should implement.”: Zamboni ( 2008 ), p. 77.

Namely, CLS “has now been around sufficiently long that is must (…) pass beyond the stage of debunking and trashing (…) [it should] grapple with the problems of advancing (…) alternative[s]”: Hunt ( 1987 ), p. 7 (personally added underlineation).

Hutchinson and Monahan ( 1984 ), p. 227 (personally added underlineation).

Hessel ( 2013 ), pp. 30–70.

Silbey and Sarat (2008), p. 502.

Fischl ( 1992 ), pp. 780–820.

The research method represents the central relationship between the main research question of a research and the (overall) strategy that enables the provision of an answer to this question. Moreover, the research method emphasises the function of the research. Taking my main research question into account, it is safe to say that the function of my research (my research method) is design. The research method of design is about proposing a change or solution to solve a problem or to improve a situation. Design is intrinsically linked to the evaluation of a (problematic) situation: Tijssen ( 1961 ), pp. 53–59. Bakshi has remarked that designing proposals for law reform either result as a by-product of the undertaken research or as the manifestation of an intention that has been specified in the beginning the research (the latter being my case): Bakshi (2001), p. 111. When the latter option is opted for, the research “is undertaken with a definite end, namely, making suggestions for improvements in the law on concrete and easily identifiable matters and the formulation of those proposals in precise terms.”: Bakshi (2001), p. 111. This process of conducting a research with the intention to design proposals of law reform generally involves slightly more than just evaluation according to Bakshi. It involves the analysis of the existing law; a historical examination (finding out what the previous law looked like in order to understand how and why it changed); a comparison; a statistical examination (if statistics are available); and a critical examination (finding out the defects or problems in the existing law on the basis of which reforms are suggested: Bakshi (2001), p. 113. The research method of design has been utilized in legal research (see Chap. 4 ) but is gaining more and more prominence outside the legal context. Examples of scholars who have designed alternative ways to structure the current political economy or alternative parts of the current political economy include the Skydelskys, Bregman and Mason: Skidelsky and Skidelsky ( 2013 ), pp. 11–218; Bregman ( 2017 ), pp. 33–72; Mason ( 2016 ), pp. 263–292.

Marano and Siri ( 2017 ), p. 16; Focarelli (2017), p. 354.

Van Hoecke ( 2011 ), p. v . To clarify, “[e]valuative scholarship is in some way providing an assessment of the way the (legal) world is , and, either implicitly or explicitly, subjecting the law to appraisal either from the point of view of coherence with earlier law , other areas of law, or from an external viewpoint and where shortfalls are identified , suggesting how things might be improved .”: Cryer et al. ( 2011 ), p. 9 (personally added underlineation). Cryer et al. ( 2011 ), p. 9.

Wendt ( 2008 ), p. 144.

Wendt ( 2008 ), pp. 132–144.

Gordon (1989), p. 384.

This assumption is shared by the legal method of comparative law. That is, “[c]omparative law is an ‘école de vérité’ which extends and enriches the ‘supply of solutions’ (Zitelmann) and offers the scholar of critical capacity the opportunity of finding the ‘better solution’ for his time and place.”: Zweigert and Kötz ( 1994 ), p. 15 (personally added underlineation).

Tushnet ( 2011 ), p. 299; Kennedy ( 1985 ), p. 1031; Hutchinson ( 1989 ), p. 10.

It needs to be specified that my comparison, borrowing from the legal method of comparative law, is based on the principle of functionality . The principle of functionality dictates that a question to which a comparison is devoted must be posed in functional terms. It must concern a concrete problem without a reference to concepts from either one of the sources that are compared: Zweigert and Kötz ( 1994 ), pp. 30–33. In my case, the concrete problem on which the comparison is based is ideology . I also need to specify that my research is not primarily using the method of comparative law since this method assumes a dimension of internationalism: Zweigert and Kötz ( 1994 ), p. 2. This dimension of internationalism is not the main focus of my comparison that primarily concerns Solvency II and its predecessor, i.e. my comparison takes place in the framework of one legal system (the EU legal system). However, Van Gerven and Lierman have indicated that the requirement of the dimension of internationalism in the method of comparative law is outdated. In the last couple of decades internal comparative law has emerged (as opposed to the comparative law described by Zweigert and Kӧtz which has been labelled as external comparative law by Van Gerven and Lierman) which is concerned with looking beyond the boundaries of a specific field in one legal system (especially in case law): Van Gerven and Lieman ( 2010 ), pp. 137–147.

Indeed, how can one design any alternatives without knowing what the law is and what it was before?: Meyendorff (1933), p. 22.

Fiss ( 1986 ), p. 10. It should be emphasised that my design of an alternative ideology does not aim to claim to be the optimal design of an alternative ideology. It is just one possible option to show that there is nothing natural and inevitable about the existing ideology. Moreover, it is one possible option that should be communicated, debated and pulled apart in society. By emphasising this I am attempting to “be careful to avoid foisting [my] own structure of thought on others”: Hutchinson and Monahan ( 1984 ), p. 229.

Shiffrin ( 2006 ), p. 178. By crafting an alternative decision for Lechmere, Inc. v. NLRB , Shiffrin did not intend to show that the Supreme Court reached the wrong decision. Rather, Shiffrin hoped to show that law should be a conversation about things that matter to us: Shiffrin ( 2006 ), p. 178. In the spirit of methodological trashing, Shiffrin designed an alternative to spark awareness and communication.

Hutchinson and Monahan ( 1984 ), p. 230.

Byttebier ( 2015 ), pp. 5–525. By now this monograph has been translated to English: Byttebier ( 2017 ), pp. vii -501. Now that the English version of this monograph is available, I will refer to it from this point on. Outside of a legal context, the monograph by the Skydelskys about how much is enough is an example of a research employing the method of design of reform. The Skydelskys have namely argued that we have lost touch with the good life and have made propositions (design) to return to it by means of a different social and economic organization. The propositions include the introduction of basic income, the reduction of the pressure to consume and the reduction of advertising: Skidelsky and Skidelsky ( 2013 ), pp. 11–218.

Within the legal method of comparative law such a distinction already exists. Namely, whenever comparative lawyers engage in a comparison of how concrete problems are dealt with in the legal systems of different nations they can do so on a large scale or a on a smaller scale. A comparison on a large is called a macrocomparison whereas a comparison on a smaller scale is called a microcomparison : Zweigert and Kötz ( 1994 ), pp. 4–5.

Hutchinson ( 1989 ), p. 8 (personally added underlineation). Hopeless, in this context seems to signify not “connected in a meaningful way to reality: Austin ( 1998 ), p. 110. Granted that being too abstract is of no use to anyone, being utopian is not necessarily a bad thing. Certainly not if thinking of alternatives and having different visions is utopian. If such is the case, then “CLS should wear the badge of utopianism with pride, for more, not less not-status-quo-oriented thinking is needed.”: Hutchinson ( 1989 ), p. 8. Also, why can’t human beings form a picture of an ideal life or a perfect society and share it with other human beings? Thoughts, debates and dreams are never wasted, especially in today’s information society (see Sect. 3.4.1.4 ): Mason ( 2016 ), pp. xviii–xxi . Moreover, the criticism of utopianism goes either way. Proponents of free markets and TINA can be criticized for being utopian just as much. For those interested in an achievable utopia (and the difference between utopia as a rigid blueprint and utopia as an alternative with the capacity to spark the imagination), see: Bregman ( 2017 ), pp. 1–316.

Schwartz ( 1984 ), p. 428.

Caudill ( 1987 ), p. 355. This vice is particularly dangerous as “the elaboration of grand schemes for future societies runs the danger of simply imposing one more form of ‘alien’ social consciousness.”: Hutchinson ( 1989 ), p. 8. However, there is something to be said for grandiose ideas. According to Bregman, Overton (an American lawyer) asked himself why a lot of good ideas simply don’t get taken seriously in the context of politics. “Overton realized that politicians, provided they want to be reelected, can’t permit themselves viewpoints that are seen as too extreme. In order to hold power, they have to keep their ideas within the margins of what’s acceptable. This window of acceptability is populated by schemes that are rubber-stamped by the experts, tallied up by statistics services, and have good odds of making it into the law books. Anybody who forays outside the ‘Overton window’ faces a rocky road. He or she will quickly be branded as ‘unrealistic’ or ‘unreasonable’ by the media, the fearsome gatekeepers of the window. (…) And yet, despite all this, a society can change completely in a few decades. The Overton Window can shift. A classic strategy for achieving this is to proclaim ideas so shocking and subversive that anything less radical suddenly sounds sensible .”: Bregman ( 2017 ), pp. 254–255 (personally added underlineation). And thus even grandiose ideas have a function. They can pave the way for a better society by making other ideas, more alternative ideologies of how to shape a social order, seem less radical and thus more sensible. A good example of such a strategy within CLS specifically was Kennedy’s proposal to inter alia establish a single salary at the Harvard Law School for everyone (from the janitor to the dean), to implement a rotation system whereby each member of the Harvard Law School would rotate through each job and to implement a system whereby university admission would operate by lot. Kennedy was partly serious about his proposals. The sentiment for the part that he was not serious about revolved around provocation and confounding: Schwartz ( 1984 ), pp. 413–414.

Schwartz ( 1984 ), p. 448.

As such I am trying to be both constructive and concrete. Namely, as Kelman points out, when Crits only trash, they are accused of nihilism. When Crits trash and actually propose alternatives, they are accused of being utopian since they allegedly do not propose concrete steps, i.e. are too vague: Kelman (1989), p. 210. Austin has also mentioned that CLS is either accused of not mentioning solutions (resulting in nihilism) or of being utopian: Austin ( 1998 ), pp. 90–110.

Mason ( 2016 ), p. xiii .

Rickards (2014), p. 292. According to Popper (and Soros, who follows Popper in this matter) it is better to introduce changes on a small (scarcely noticeable) scale rather than to directly propose changes on a large scale as the first assumes graduality which has a larger chance to succeed anything drastic: Rickards (2014), p. 292.

Mason ( 2016 ), p. 277.

Unger (2015), p. 29.

Bibliography

Austin A (1998) The empire strikes back: outsiders and the struggle over legal education. New York University Press, New York

Google Scholar  

Bregman R (2017) Utopia for realists: and how we can get there. Bloomsbury, London

Byttebier K (2015) Nu het gouden kalf verdronken is: Van hebzucht naar altruïsme als hoeksteen voor een Nieuwe Monetaire Wereldorde. Maklu, Antwerp

Byttebier K (2017) Towards a new international monetary order. Springer, Sham

Book   Google Scholar  

Caudill DS (1987) Disclosing tilt: a partial defence of critical legal studies and a comparative introduction to the philosophy of the law-idea. Iowa Law Rev 72:287–359

Cryer R, Hervey T, Sokhi-Bulley B (2011) Research methodologies in EU and international law. Hart, Oxford

Fischl M (1992) The question that killed critical legal studies. Law Soc Inq 17:779–820

Article   Google Scholar  

Fiss OM (1986) Death of the law. Cornell Law Rev 72:1–16

Freeman AD (1981) Truth and mystification in legal scholarship. Yale Law J 90:1229–1237

Gabel P (2009) Critical legal studies as a spiritual practice. Pepp Law Rev 36:515–534

Gordon RW (1998) Law and ideology. Tikkun 3:14–87

Hessel S (2013) Neem het niet. Van Gennep, Amsterdam

Hunt A (1987) The critique of law: what is ‘critical’ about critical legal theory? J Law Soc 14:5–19

Hutchinson AC (ed) (1989) Critical legal studies. Rowman & Littlefield Publishers, Totowa

Hutchinson AC, Monahan PJ (1984) Law, politics and the critical legal scholars: the unfolding Drama of American legal thought. Stan Law Rev 36:199–235

Kairys D (ed) (1998) The politics of law: a progressive critique. Basic Books, New York

Katz SN (ed) (2009) The Oxford international Encyclopedia of legal history. Oxford University Press, Oxford

Kelman M (1987) A guide to critical legal studies. Harvard University Press, Cambridge

Kennedy D (1985) Afterword. Psycho-social CLS: a comment on the Cardozo Symposium. Cardozo Law Rev 6:1013–1031

London School of Economics and Political Science (ed) (1933) Modern theories of law. Oxford University Press, London

Marano P, Siri M (eds) (2017) Insurance regulation in the European Union: solvency II and beyond. Palgrave Macmillan, Cham

Mason P (2016) Post capitalism: a guide to our future. Penguin Books, London

Mertz E (ed) (2008) The role of social science in law. Ashgate, Hampshire

Russell JS (1986) The critical legal studies challenge to contemporary mainstream legal philosophy. Ottowa Law 18:1–24

Schwartz LB (1984) With gun and camera through darkest CLS-land. Stan Law Rev 1984(36):413–464

Shiffrin JB (2006) A practical jurisprudence of values: re-writing Lechmere, Inc. v. NLRB. Harv Civ Rights-Civ Libr Law Rev 41:177–217

Skidelsky R, Skidelsky E (2013) How much is enough? Money and the good life. Penguin Books, London

Tijssen HEB (1961) De juridische dissertatie onder de loep: De verantwoording van methodologische keuzes in juridische dissertaties. Dissertation, University of Tilburg

Tushnet M (2011) Some current controversies in critical legal studies. German Law J 12:290–299

Van Gerven W, Lierman S (2010) Algemeen Deel Veertig jaar later: Privaat-en Publiekrecht in een Meergelaagd kader van regelgeving, rechtsvorming en regeltoepassing, I, Beginselen van Belgisch Privaatrecht. Kluwer, Mechelen

Van Hoecke M (ed) (2011) Methodologies of legal research: which kind of method for what kind of discipline? Hart, Oxford

Verma SK, Afzal Wani M (eds) (2001) Legal research and methodology. Indian Law Institute, New Delhi

Wendt JAI (2008) De methode der rechtswetenschap vanuit kritisch-rationeel perspectief. Dissertation, Erasmus University of Rotterdam

Williams J (2011) Is law and art [sic] or a science?: Comments on objectivity, feminism and power. JGSPL 7:355–372

Zamboni M (2008) Law and politics: a dilemma for contemporary legal theory. Springer, Berlin

Zweigert K, Kötz H (1994) An introduction to comparative law. Clarendon Press, Oxford

Download references

Author information

Authors and affiliations.

ECOR and ETAF, Vrije Universiteit Brussel, Brussels, Belgium

Kristina Loguinova

You can also search for this author in PubMed   Google Scholar

Rights and permissions

Reprints and permissions

Copyright information

© 2019 Springer Nature Switzerland AG

About this chapter

Loguinova, K. (2019). The Research Method: Law Reform Design. In: A Critical Legal Study of the Ideology Behind Solvency II. Economic and Financial Law & Policy – Shifting Insights & Values, vol 4. Springer, Cham. https://doi.org/10.1007/978-3-030-26357-7_4

Download citation

DOI : https://doi.org/10.1007/978-3-030-26357-7_4

Published : 18 October 2019

Publisher Name : Springer, Cham

Print ISBN : 978-3-030-26356-0

Online ISBN : 978-3-030-26357-7

eBook Packages : Law and Criminology Law and Criminology (R0)

Share this chapter

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Publish with us

Policies and ethics

• Find a journal
• Track your research

Critical Legal Research: Who Needs It?

112 Law Library Journal 327 (2020)

17 Pages Posted: 21 Apr 2021

Nicholas Mignanelli

Yale Law School

Date Written: April 20, 2021

This article builds on prior works to develop a framework for practicing and teaching Critical Legal Research in such a way as “to prepare a free relationship” between the researcher and AI-powered legal research. The author argues that it is only in doing so that legal innovation will continue to be possible.

Keywords: critical legal research, critical legal information, critical librarianship, legal research, artificial intelligence

Suggested Citation: Suggested Citation

Nicholas Mignanelli (Contact Author)

Yale law school ( email ).

127 Wall Street New Haven, CT 06510 United States

Do you have a job opening that you would like to promote on SSRN?

Paper statistics, related ejournals, legal writing ejournal.

Subscribe to this free journal for more curated articles on this topic

Legal Information, Technology & Law Librarianship eJournal

Subscribe to this fee journal for more curated articles on this topic

Artificial Intelligence - Law, Policy, & Ethics eJournal

Legal Research Strategy

Preliminary analysis, organization, secondary sources, primary sources, updating research, identifying an end point, getting help, about this guide.

This guide will walk a beginning researcher though the legal research process step-by-step. These materials are created with the 1L Legal Research & Writing course in mind. However, these resources will also assist upper-level students engaged in any legal research project.

How to Strategize

Legal research must be comprehensive and precise.  One contrary source that you miss may invalidate other sources you plan to rely on.  Sticking to a strategy will save you time, ensure completeness, and improve your work product. 

Follow These Steps

Running Time: 3 minutes, 13 seconds.

Make sure that you don't miss any steps by using our:

• Legal Research Strategy Checklist

If you get stuck at any time during the process, check this out:

• Ten Tips for Moving Beyond the Brick Wall in the Legal Research Process, by Marsha L. Baum

Understanding the Legal Questions

A legal question often originates as a problem or story about a series of events. In law school, these stories are called fact patterns. In practice, facts may arise from a manager or an interview with a potential client. Start by doing the following:

• Read anything you have been given
• Analyze the facts and frame the legal issues
• Assess what you know and need to learn
• Note the jurisdiction and any primary law you have been given
• Generate potential search terms

Jurisdiction

Legal rules will vary depending on where geographically your legal question will be answered. You must determine the jurisdiction in which your claim will be heard. These resources can help you learn more about jurisdiction and how it is determined:

• Legal Treatises on Jurisdiction
• LII Wex Entry on Jurisdiction

This map indicates which states are in each federal appellate circuit:

Getting Started

Once you have begun your research, you will need to keep track of your work. Logging your research will help you to avoid missing sources and explain your research strategy. You will likely be asked to explain your research process when in practice. Researchers can keep paper logs, folders on Westlaw or Lexis, or online citation management platforms.

Organizational Methods

Tracking with paper or excel.

Many researchers create their own tracking charts.  Be sure to include:

• Search Date
• Topics/Keywords/Search Strategy
• Citation to Relevant Source Found
• Save Locations
• Follow Up Needed

Consider using the following research log as a starting place: 

• Sample Research Log

Tracking with Folders

Westlaw and Lexis offer options to create folders, then save and organize your materials there.

• Lexis Advance Folders
• Westlaw Edge Folders

Tracking with Citation Management Software

For long term projects, platforms such as Zotero, EndNote, Mendeley, or Refworks might be useful. These are good tools to keep your research well organized. Note, however, that none of these platforms substitute for doing your own proper Bluebook citations. Learn more about citation management software on our other research guides:

• Guide to Zotero for Harvard Law Students by Harvard Law School Library Research Services Last Updated Aug 9, 2024 399 views this year
• Zotero by Daniel Becker Last Updated Aug 30, 2024 26520 views this year

Types of Sources

There are three different types of sources: Primary, Secondary, and Tertiary.  When doing legal research you will be using mostly primary and secondary sources.  We will explore these different types of sources in the sections below.

Secondary sources often explain legal principles more thoroughly than a single case or statute. Starting with them can help you save time.

Secondary sources are particularly useful for:

• Learning the basics of a particular area of law
• Understanding key terms of art in an area
• Identifying essential cases and statutes

Consider the following when deciding which type of secondary source is right for you:

• Scope/Breadth
• Depth of Treatment
• Currentness/Reliability

For a deep dive into secondary sources visit:

• Secondary Sources: ALRs, Encyclopedias, Law Reviews, Restatements, & Treatises by Catherine Biondo Last Updated Apr 12, 2024 6439 views this year

Legal Dictionaries & Encyclopedias

Legal dictionaries.

Legal dictionaries are similar to other dictionaries that you have likely used before.

• Black's Law Dictionary
• Ballentine's Law Dictionary

Legal Encyclopedias

Legal encyclopedias contain brief, broad summaries of legal topics, providing introductions and explaining terms of art. They also provide citations to primary law and relevant major law review articles.  

Here are the two major national encyclopedias:

• American Jurisprudence (AmJur) (Westlaw)
• American Jurisprudence (Lexis)
• Corpus Juris Secundum (CJS)

Treatises are books on legal topics.  These books are a good place to begin your research.  They provide explanation, analysis, and citations to the most relevant primary sources. Treatises range from single subject overviews to deep treatments of broad subject areas.

It is important to check the date when the treatise was published. Many are either not updated, or are updated through the release of newer editions.

To find a relevant treatise explore:

• Legal Treatises by Subject by Catherine Biondo Last Updated Apr 12, 2024 6029 views this year

American Law Reports (ALR)

American Law Reports (ALR) contains in-depth articles on narrow topics of the law. ALR articles, are often called annotations. They provide background, analysis, and citations to relevant cases, statutes, articles, and other annotations. ALR annotations are invaluable tools to quickly find primary law on narrow legal questions.

This resource is available in both Westlaw and Lexis:

• American Law Reports on Westlaw (includes index)
• American Law Reports on Lexis

Law Reviews & Journals

Law reviews are scholarly publications, usually edited by law students in conjunction with faculty members. They contain both lengthy articles and shorter essays by professors and lawyers. They also contain comments, notes, or developments in the law written by law students. Articles often focus on new or emerging areas of law and may offer critical commentary. Some law reviews are dedicated to a particular topic while others are general. Occasionally, law reviews will include issues devoted to proceedings of panels and symposia.

Law review and journal articles are extremely narrow and deep with extensive references. 

To find law review articles visit:

• Law Journal Library on HeinOnline
• Law Reviews & Journals on LexisNexis
• Law Reviews & Journals on Westlaw

Restatements

Restatements are highly regarded distillations of common law, prepared by the American Law Institute (ALI). ALI is a prestigious organization comprised of judges, professors, and lawyers. They distill the "black letter law" from cases to indicate trends in common law. Resulting in a “restatement” of existing common law into a series of principles or rules. Occasionally, they make recommendations on what a rule of law should be.

Restatements are not primary law. However, they are considered persuasive authority by many courts.

Restatements are organized into chapters, titles, and sections.  Sections contain the following:

• a concisely stated rule of law,
• comments to clarify the rule,
• hypothetical examples,
• explanation of purpose, and
• exceptions to the rule  

To access restatements visit:

• American Law Institute Library on HeinOnline
• Restatements & Principles of the Law on LexisNexis
• Restatements & Principles of Law on Westlaw

Primary Authority

Primary authority is "authority that issues directly from a law-making body."   Authority , Black's Law Dictionary (11th ed. 2019).   Sources of primary authority include:

• Constitutions
• Statutes 

Regulations

Access to primary legal sources is available through:

• Bloomberg Law
• Free & Low Cost Alternatives

Statutes (also called legislation) are "laws enacted by legislative bodies", such as Congress and state legislatures.  Statute , Black's Law Dictionary (11th ed. 2019).

We typically start primary law research here. If there is a controlling statute, cases you look for later will interpret that law. There are two types of statutes, annotated and unannotated.

Annotated codes are a great place to start your research. They combine statutory language with citations to cases, regulations, secondary sources, and other relevant statutes. This can quickly connect you to the most relevant cases related to a particular law. Unannotated Codes provide only the text of the statute without editorial additions. Unannotated codes, however, are more often considered official and used for citation purposes.

For a deep dive on federal and state statutes, visit:

• Statutes: US and State Codes by Mindy Kent Last Updated Apr 12, 2024 4814 views this year
• 50 State Surveys

Want to learn more about the history or legislative intent of a law?  Learn how to get started here:

• Legislative History Get an introduction to legislative histories in less than 5 minutes.
• Federal Legislative History Research Guide

Regulations are rules made by executive departments and agencies. Not every legal question will require you to search regulations. However, many areas of law are affected by regulations. So make sure not to skip this step if they are relevant to your question.

To learn more about working with regulations, visit:

• Administrative Law Research by AJ Blechner Last Updated Apr 12, 2024 815 views this year

Case Basics

In many areas, finding relevant caselaw will comprise a significant part of your research. This Is particularly true in legal areas that rely heavily on common law principles.

Running Time: 3 minutes, 10 seconds.

Unpublished Cases

Up to  86% of federal case opinions are unpublished. You must determine whether your jurisdiction will consider these unpublished cases as persuasive authority. The Federal Rules of Appellate Procedure have an overarching rule, Rule 32.1  Each circuit also has local rules regarding citations to unpublished opinions. You must understand both the Federal Rule and the rule in your jurisdiction.

• Federal and Local Rules of Appellate Procedure 32.1 (Dec. 2021).
• Type of Opinion or Order Filed in Cases Terminated on the Merits, by Circuit (Sept. 2021).

Each state also has its own local rules which can often be accessed through:

• State Bar Associations
• State Courts Websites

First Circuit

• First Circuit Court Rule 32.1.0

Second Circuit

• Second Circuit Court Rule 32.1.1

Third Circuit

• Third Circuit Court Rule 5.7

Fourth Circuit

• Fourth Circuit Court Rule 32.1

Fifth Circuit

• Fifth Circuit Court Rule 47.5

Sixth Circuit

• Sixth Circuit Court Rule 32.1

Seventh Circuit

• Seventh Circuit Court Rule 32.1

Eighth Circuit

• Eighth Circuit Court Rule 32.1A

Ninth Circuit

• Ninth Circuit Court Rule 36-3

Tenth Circuit

• Tenth Circuit Court Rule 32.1

Eleventh Circuit

• Eleventh Circuit Court Rule 32.1

D.C. Circuit

• D.C. Circuit Court Rule 32.1

Federal Circuit

• Federal Circuit Court Rule 32.1

Finding Cases

Headnotes show the key legal points in a case. Legal databases use these headnotes to guide researchers to other cases on the same topic. They also use them to organize concepts explored in cases by subject. Publishers, like Westlaw and Lexis, create headnotes, so they are not consistent across databases.

Headnotes are organized by subject into an outline that allows you to search by subject. This outline is known as a "digest of cases." By browsing or searching the digest you can retrieve all headnotes covering a particular topic. This can help you identify particularly important cases on the relevant subject.

Running Time: 4 minutes, 43 seconds.

Each major legal database has its own digest:

• Topic Navigator (Lexis)
• Key Digest System (Westlaw)

Start by identifying a relevant topic in a digest.  Then you can limit those results to your jurisdiction for more relevant results.  Sometimes, you can keyword search within only the results on your topic in your jurisdiction.  This is a particularly powerful research method.

One Good Case Method

After following the steps above, you will have identified some relevant cases on your topic. You can use good cases you find to locate other cases addressing the same topic. These other cases often apply similar rules to a range of diverse fact patterns.

• in Lexis click "More Like This Headnote"
• in Westlaw click "Cases that Cite This Headnote"

to focus on the terms of art or key words in a particular headnote. You can use this feature to find more cases with similar language and concepts.  ​

Ways to Use Citators

A citator is "a catalogued list of cases, statutes, and other legal sources showing the subsequent history and current precedential value of those sources.  Citators allow researchers to verify the authority of a precedent and to find additional sources relating to a given subject." Citator , Black's Law Dictionary (11th ed. 2019).

Each major legal database has its own citator.  The two most popular are Keycite on Westlaw and Shepard's on Lexis.

• Keycite Information Page
• Shepard's Information Page

Making Sure Your Case is Still Good Law

This video answers common questions about citators:

For step-by-step instructions on how to use Keycite and Shepard's see the following:

Additional Shepard's Resources

• Shepard's Video Tutorial
• Shepard's Handout
• Shepard's Editorial Phrase Dictionary
• Shepard's Signal Indicators & Analysis Phrases
• Shepard's Citation Services User Guide
• Lexis+ Support and Training Additional online videos and handouts for Lexis+.

Additional KeyCite Resources

• How to Ensure I'm Citing Good Law (Westlaw Video)
• KeyCite Handout
• KeyCite Editorial Phrase Dictionary
• Understanding Next Generation KeyCite
• How to Check the Status of a Case with KeyCite
• Westlaw Precision Support Additional videos and handouts to support your Westlaw research.

Using Citators For

Citators serve three purposes: (1) case validation, (2) better understanding, and (3) additional research.

Case Validation

Is my case or statute good law?

• Parallel citations
• Prior and subsequent history
• Negative treatment suggesting you should no longer cite to holding.

Better Understanding

Has the law in this area changed?

• Later cases on the same point of law
• Positive treatment, explaining or expanding the law.
• Negative Treatment, narrowing or distinguishing the law.

Track Research

Who is citing and writing about my case or statute?

• Secondary sources that discuss your case or statute.
• Cases in other jurisdictions that discuss your case or statute.

Knowing When to Start Writing

For more guidance on when to stop your research see:

• Terminating Research, by Christina L. Kunz

Contact Us!

  Ask Us!  Submit a question or search our knowledge base.

Chat with us!  Chat   with a librarian (HLS only)

Email: [email protected]

 Contact Historical & Special Collections at [email protected]

  Meet with Us   Schedule an online consult with a Librarian

Hours  Library Hours

Classes  View  Training Calendar  or  Request an Insta-Class

 Text  Ask a Librarian, 617-702-2728

 Call  Reference & Research Services, 617-495-4516

This guide is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License .

You may reproduce any part of it for noncommercial purposes as long as credit is included and it is shared in the same manner. 

• Last Updated: Aug 27, 2024 5:19 PM
• URL: https://guides.library.harvard.edu/law/researchstrategy

Harvard University Digital Accessibility Policy

Legal Dissertation: Research and Writing Guide

About this guide, video on choosing a topic, tools on westlaw, lexis and bloomberg, circuit splits, research methodologies, additional methodology resources, conducting a literature review, beginning research, writing style guides, citation guides, ask a librarian.

Ask a librarian:

Reference Hours:

Monday - Friday: 9am-5pm

(812) 855-2938

Q&A Form

About This Page

Choosing a topic can be one of the most challenging aspects of writing an extensive paper. This page has resources to help you find topics and inspiration, before you get started on the in-depth research process.

Related Guides

Citation and Writing Resources

Legal Research Tutorials

Secondary Sources for Legal Research

Methods of Finding Cases

Methods of Finding Statutes

Current Awareness and Alerting Resources

Compiling State Legislative Histories

Locating International and Foreign Law Journals

This guide contains resources to help students researching and writing a legal dissertation or other upper-level writing project. Some of the resources in this guide are directed at researching and writing in general, not specifically on legal topics, but the strategies and tips can still be applied.

The Law Library maintains a number of other guides on related skills and topics that may be of interest:

The Wells Library also maintains guides. A few that may be helpful for managing research can be found here:

Choosing a Topic

This video discusses tips and strategies for choosing a dissertation topic.

Note: this video is not specific to legal dissertation topics, but it may still be of interest as an overview generally.

The Bloomberg/BNA publication United States Law Week can be a helpful resource for tracking down the major legal stories of the day.  Log into Bloomberg Law, in the big search box, start typing United States Law Week and the title will appear in the drop down menu beneath the box. This publication provides coverage of top legal news stories, and in-depth "insight" features.

If you have a general idea of the area of law you wish to write about, check out the Practice Centers on Bloomberg. From the homepage, click the Browse link in the top left-hand corner. Then select Practice Centers and look for your area of law. Practice Centers are helpful because they gather cases, statutes, administrative proceedings, news, and more on the selected legal area.

Bloomberg has other news sources available as well. From the homepage, click the Browse link in the top left-hand corner. Then select News and Analysis, then select News or Analysis, and browse the available topics.

If you know what area of law you'd like to write about, you may find the Browse Topics feature in Lexis Advance helpful for narrowing down your topic. 

Log into Lexis Advance, click the Browse Topics tab, and select a topic.  If you don't see your topic listed, try using the provided search bar to see whether your topic is categorized as a sub-topic within this list. 

Once you click on a topic, a box pops up with several options.  If you click on Get Topic Document, you'll see results listed in a number of categories, including Cases, Legislation, and more.  The News and Legal News categories at the right end of the list may help you identify current developments of interest for your note.  Don't forget about the filtering options on the left that will allow you to search within your results, narrow your jurisdiction, and more.

Similar to Lexis Advance, Westlaw Edge has a Topics tab that may be helpful if you know what area of law you'd like to write about.

Log onto Westlaw Edge, and click on the Topics tab.  This time, you won't be able to search within this list, so if you're area is not listed, you should either run a regular search from the main search bar at the top or try out some of the topics listed under this tab - once you click on a topic, you can search within its contents.

What is great about the Topics in Westlaw Edge is the Practitioner Insights page you access by clicking on a topic.  This is an information portal that allows you quick access to cases, legislation, top news, and more on your selected topic.

In United States federal courts, a circuit split occurs whenever two or more circuit courts of appeals issue conflicting rulings on the same legal question. Circuit splits are ripe for legal analysis and commentary because they present a situation in which federal law is being applied in different ways in different parts of the country, even if the underlying litigants themselves are otherwise similarly situated. The Supreme Court also frequently accepts cases on appeal that involve these types of conflicted rulings from various sister circuits.

To find a circuit split on a topic of interest to you, try searching on Lexis and Westlaw using this method:

in the search box, enter the following: (circuit or court w/s split) AND [insert terms or phrases to narrow the search]

You can also browse for circuit splits on Bloomberg. On the Bloomberg homepage, in the "Law School Success" box, Circuit Splits Charts appear listed under Secondary Sources.

Other sources for circuit splits are American Law Reports (ALR) and American Jurisprudence (AmJur). These publications provide summaries of the law, point out circuit splits, and provide references for further research.

"Blawgs" or law-related blogs are often written by scholars or practitioners in the legal field.  Ordinarily covering current events and developments in law, these posts can provide inspiration for note topics.  To help you find blawgs on a specific topic, consider perusing the ABA's Blawg Directory or Justia's Blawg Search .

Research Methodology

Types of research methodologies.

There are different types of research methodologies. Methodology refers to the strategy employed in conducting research. The following methodologies are some of the most commonly used in legal and social science research.

Doctrinal legal research methodology, also called "black letter" methodology, focuses on the letter of the law rather than the law in action. Using this method, a researcher composes a descriptive and detailed analysis of legal rules found in primary sources (cases, statutes, or regulations). The purpose of this method is to gather, organize, and describe the law; provide commentary on the sources used; then, identify and describe the underlying theme or system and how each source of law is connected.

Doctrinal methodology is good for areas of law that are largely black letter law, such as contract or property law. Under this approach, the researcher conducts a critical, qualitative analysis of legal materials to support a hypothesis. The researcher must identify specific legal rules, then discuss the legal meaning of the rule, its underlying principles, and decision-making under the rule (whether cases interpreting the rule fit together in a coherent system or not). The researcher must also identify ambiguities and criticisms of the law, and offer solutions. Sources of data in doctrinal research include the rule itself, cases generated under the rule, legislative history where applicable, and commentaries and literature on the rule.

This approach is beneficial by providing a solid structure for crafting a thesis, organizing the paper, and enabling a thorough definition and explanation of the rule. The drawbacks of this approach are that it may be too formalistic, and may lead to oversimplifying the legal doctrine.

Comparative

Comparative legal research methodology involves critical analysis of different bodies of law to examine how the outcome of a legal issue could be different under each set of laws. Comparisons could be made between different jurisdictions, such as comparing analysis of a legal issue under American law and the laws of another country, or researchers may conduct historical comparisons.

When using a comparative approach be sure to define the reasons for choosing this approach, and identify the benefits of comparing laws from different jurisdictions or time periods, such as finding common ground or determining best practices and solutions. The comparative method can be used by a researcher to better understand their home jurisdiction by analyzing how other jurisdictions handle the same issue. This method can also be used as a critical analytical tool to distinguish particular features of a law. The drawback of this method is that it can be difficult to find material from other jurisdictions. Also, researchers should be sure that the comparisons are relevant to the thesis and not just used for description.

This type of research uses data analysis to study legal systems. A detailed guide on empirical methods can be found here . The process of empirical research involves four steps: design the project, collect and code the data, analyze the data, determine best method of presenting the results. The first step, designing the project, is when researchers define their hypothesis and concepts in concrete terms that can be observed. Next, researchers must collect and code the data by determining the possible sources of information and available collection methods, and then putting the data into a format that can be analyzed. When researchers analyze the data, they are comparing the data to their hypothesis. If the overlap between the two is significant, then their hypothesis is confirmed, but if there is little to no overlap, then their hypothesis is incorrect. Analysis involves summarizing the data and drawing inferences. There are two types of statistical inference in empirical research, descriptive and causal. Descriptive inference is close to summary, but the researcher uses the known data from the sample to draw conclusions about the whole population. Causal inference is the difference between two descriptive inferences.

Two main types of empirical legal research are qualitative and quantitative.

Quantitative, or numerical, empirical legal research involves taking information about cases and courts, translating that information into numbers, and then analyzing those numbers with statistical tools.

Qualitative, or non-numerical, empirical legal research involves extracting  information from the text of court documents, then interpreting and organizing the text into categories, and using that information to identify patterns.

Drafting The Methodology Section

This is the part of your paper that describes the research methodology, or methodologies if you used more than one. This section will contain a detailed description of how the research was conducted and why it was conducted in that way. First, draft an outline of what you must include in this section and gather the information needed.

Generally, a methodology section will contain the following:

• Statement of research objectives
• Reasons for the research methodology used
• Description and rationale of the data collection tools, sampling techniques, and data sources used, including a description of how the data collection tools were administered
• Discussion of the limitations
• Discussion of the data analysis tools used

Be sure that you have clearly defined the reasoning behind the chosen methodology and sources.

• Legal Reasoning, Research, and Writing for International Graduate Students Nadia E. Nedzel Aspen (2004) A guide to American legal research and the federal system, written for international students. Includes information on the research process, and tips for writing. Located in the Law Library, 3rd Floor: KF 240 .N43 2004.
• Methodologies of Legal Research: Which Kind of Method for What Kind of Discipline? Mark van Hoecke Oxford (2013) This book examines different methods of legal research including doctrinal, comparative, and interdisciplinary. Located at Lilly Law Library, Indianapolis, 2nd Floor: K 235 .M476 2013. IU students may request item via IUCAT.
• An Introduction to Empirical Legal Research Lee Epstein and Andrew D. Martin Oxford University Press (2014) This book includes information on designing research, collecting and coding data, analyzing data, and drafting the final paper. Located at Lilly Law Library, Indianapolis, 2nd Floor: K 85 .E678 2014. IU students may request item via IUCAT.
• Emplirical Legal Studies Blog The ELS blog was created by several law professors, and focuses on using empirical methods in legal research, theory, and scholarship. Search or browse the blog to find entries on methodology, data sources, software, and other tips and techniques.

Literature Review

The literature review provides an examination of existing pieces of research, and serves as a foundation for further research. It allows the researcher to critically evaluate existing scholarship and research practices, and puts the new thesis in context. When conducting a literature review, one should consider the following: who are the leading scholars in the subject area; what has been published on the subject; what factors or subtopics have these scholars identified as important for further examination; what research methods have others used; what were the pros and cons of using those methods; what other theories have been explored.

The literature review should include a description of coverage. The researcher should describe what material was selected and why, and how those selections are relevant to the thesis. Discuss what has been written on the topic and where the thesis fits in the context of existing scholarship. The researcher should evaluate the sources and methodologies used by other researchers, and describe how the thesis different.

The following video gives an overview of conducting a literature review.

Note: this video is not specific to legal literature, however it may be helpful as a general overview.

Not sure where to start? Here are a few suggestions for digging into sources once you have selected a topic.

Research Guides

Research guides are discovery tools, or gateways of information. They pull together lists of sources on a topic. Some guides even offer brief overviews and additional research steps specifically for that topic. Many law libraries offer guides on a variety of subjects. You can locate guides by visiting library websites, such as this Library's site , the Law Library of Congress , or other schools like Georgetown . Some organizations also compile research guides, such as the American Society of International Law . Utilizing a research guide on your topic to generate an introductory source list can save you valuable time.

Secondary Sources

It is often a good idea to begin research with secondary sources. These resources summarize, explain, and analyze the law. They also provide references to primary sources and other secondary sources. This saves you time and effort, and can help you quickly identify major themes under your topic and help you place your thesis in context.

Encyclopedias provide broad coverage of all areas of the law, but do not go in-depth on narrow topics, or discuss differences by jurisdiction, or  include all of the pertinent cases. American Jurisprudence ( AmJur ) and Corpus Juris Secundum ( CJS ) have nationwide coverage, while the Indiana Law Encyclopedia focuses on Indiana state law. A number of other states also have their own state-specific encyclopedias.

American Law Reports ( ALR ) are annotations that synopsize various cases on narrow legal topics. Each annotation covers a different topic, and provides a leading or typical case on the topic, plus cases from different jurisdictions that follow different rules, or cases where different facts applying the same rule led to different outcomes. The annotations also refer to other secondary sources.  

Legal periodicals include several different types of publications such as law reviews from academic institutions or organizations, bar journals, and commercial journals/newspapers/newsletters. Legal periodicals feature articles that describe the current state of the law and often explore underlying policies. They also critique laws, court decisions, and policies, and often advocate for changes. Articles also discuss emerging issues and notify the profession of new developments. Law reviews can be useful for in-depth coverage on narrow topics, and references to primary and other secondary sources. However, content can become outdated and researchers must be mindful of biases in articles. 

Treatises/Hornbooks/Practice Guides are a type of secondary source that provides comprehensive coverage of a legal subject. It could be broad, such as a treatise covering all of contract law, or very narrow such as a treatise focused only on search and seizure cases. These sources are good when you have some general background on the topic, but you need more in-depth coverage of the legal rules and policies. Treatises are generally well organized, and provide you with finding aids (index, table of contents, etc.) and extensive footnotes or endnotes that will lead you to primary sources like cases, statutes, and regulations. They may also include appendices with supporting material like forms. However, treatises may not be updated as frequently as other sources and may not cover your specific issue or jurisdiction.

Citation and Writing Style

• Legal Writing in Plain English Bryan A. Garner University of Chicago Press, 2001. Call # KF 250 .G373 2001 Location: Law Library, 3rd Floor Provides lawyers, judges, paralegals, law students, and legal scholars with sound advice and practical tools for improving their written work. The leading guide to clear writing in the field, this book offers valuable insights into the writing process: how to organize ideas, create and refine prose, and improve editing skills. This guide uses real-life writing samples that Garner has gathered through decades of teaching experience. Includes sets of basic, intermediate, and advanced exercises in each section.
• The Elements of Legal Style Bryan A. Garner Oxford University Press, 2002. Call # KF 250 .G37 2002 Location: Law Library, 1st Floor, Reference This book explains the full range of what legal writers need to know: mechanics, word choice, structure, and rhetoric, as well as all the special conventions that legal writers should follow in using headings, defined terms, quotations, and many other devices. Garner also provides examples from highly regarded legal writers, including Oliver Wendell Holmes, Clarence Darrow, Frank Easterbrook, and Antonin Scalia.
• Grammarly Blog Blog featuring helpful information about quirks of the English language, for example when to use "affect" or "effect" and other tips. Use the search feature to locate an article relevant to your grammar query.
• Plain English for Lawyers Richard C. Wydick Carolina Academic Press, 2005. Call # KF 250 .W9 2005 Location: Law Library, 3rd Floor Award-winning book that contains guidance to improve the writing of lawyers and law students and to promote the modern trend toward a clear, plain style of legal writing. Includes exercises at the end of each chapter.
• The Chicago Manual of Style University of Chicago Press, 2010. Call # Z 253 .U69 2010 Location: Law Library, 2nd Floor While not addressing legal writing specifically, The Chicago Manual of Style is one of the most widely used and respected style guides in the United States. It focuses on American English and deals with aspects of editorial practice, including grammar and usage, as well as document preparation and formatting.
• The Chicago Manual of Style (Online) Bryan A. Garner and William S. Strong The University of Chicago Press, 2017. Online edition: use the link above to view record in IUCAT, then click the Access link (for IU students only).
• The Bluebook Compiled by the editors of the Columbia Law Review, the Harvard Law Review, the University of Pennsylvania Law Review, and the Yale Law Journal. Harvard Law Review Association, 2015. Call # KF245 .B58 2015 Location: Law Library, 1st Floor, Circulation Desk The Bluebook: A Uniform System of Citation is a style guide that prescribes the most widely used legal citation system in the United States. The Bluebook is taught and used at a majority of U.S. law schools, law reviews and journals, and used in a majority of U.S. federal courts.
• User's Guide to the Bluebook Alan L. Dworsky William S. Hein & Co., Inc., 2015. Call # KF 245 .D853 2015 Location: Law Library, Circulation Desk "This User's Guide is written for practitioners (law students, law clerks, lawyers, legal secretaries and paralegals), and is designed to make the task of mastering citation form as easy and painless as possible. To help alleviate the obstacles faced when using proper citation form, this text is set up as a how-to manual with a step-by-step approach to learning the basic skills of citation and includes the numbers of the relevant Bluebook rules under most chapter subheadings for easy reference when more information is needed"--Provided by the publisher.
• Legal Citation in a Nutshell Larry L. Teply West Academic Publishing, 2016. Call # KF 245 .T47 2016 Location: Law Library, 1st Floor, Circulation Desk This book is designed to ease the task of learning legal citation. It initially focuses on conventions that underlie all accepted forms and systems of legal citation. Building on that understanding and an explanation of the “process” of using citations in legal writing, the book then discusses and illustrates the basic rules.
• Introduction to Basic Legal Citation (Online) Peter W. Martin Cornell Legal Information Institute, 2017. Free online resource. Includes a thorough review of the relevant rules of appellate practice of federal and state courts. It takes account of the latest edition of The Bluebook, published in 2015, and provides a correlation table between this free online citation guide and the Bluebook.
• Last Updated: Oct 24, 2019 11:00 AM
• URL: https://law.indiana.libguides.com/dissertationguide

To read this content please select one of the options below:

Please note you do not have access to teaching notes, analyzing the law qualitatively.

Qualitative Research Journal

ISSN : 1443-9883

Article publication date: 14 September 2022

Issue publication date: 4 January 2023

This article develops a methodological framework to support qualitative analyses of legal texts. Scholars across the social sciences and humanities use qualitative methods to study legal phenomena but often overlook formal legal texts as productive sites for analysis. Moreover, when qualitative researchers do analyze legal texts, they rarely discuss the methodological underpinnings that support their approach. A thorough consideration of the methodological underpinnings of qualitative approaches to legal analysis is therefore warranted.

Design/methodology/approach

By bringing critical legal theory into conversation with qualitative methodology, this article outlines a set of key principles to inform qualitative approaches to reading the law.

To construct this methodological framework, this article first distinguishes between qualitative approaches to textual analysis and the doctrinal approaches undertaken in legal practice and formal legal scholarship. It then considers how this qualitative approach might be applied to one particular genre of legal text: namely, judicial opinions, otherwise known as reasons for judgment. In doing so, it argues that robust qualitative analyses of legal texts must consider the unique characteristics of those texts, such as their distinct form, voice, rhetorical structure, and performative capabilities.

Originality/value

The methodological framework outlined here should encourage qualitative researchers to approach legal texts more readily and challenge the hegemony of doctrinal approaches to legal interpretation in social science research.

• Qualitative data analysis
• Methodological theory
• Socio-legal research methods
• Legal judgments
• Judicial opinions

Mitchell, M. (2023), "Analyzing the law qualitatively", Qualitative Research Journal , Vol. 23 No. 1, pp. 102-113. https://doi.org/10.1108/QRJ-04-2022-0061

Emerald Publishing Limited

Copyright © 2022, Emerald Publishing Limited

Related articles

All feedback is valuable.

Please share your general feedback

Report an issue or find answers to frequently asked questions

Contact Customer Support

• Search Menu

Sign in through your institution

• Browse content in Arts and Humanities
• Browse content in Archaeology
• Anglo-Saxon and Medieval Archaeology
• Archaeological Methodology and Techniques
• Archaeology by Region
• Archaeology of Religion
• Archaeology of Trade and Exchange
• Biblical Archaeology
• Contemporary and Public Archaeology
• Environmental Archaeology
• Historical Archaeology
• History and Theory of Archaeology
• Industrial Archaeology
• Landscape Archaeology
• Mortuary Archaeology
• Prehistoric Archaeology
• Underwater Archaeology
• Zooarchaeology
• Browse content in Architecture
• Architectural Structure and Design
• History of Architecture
• Residential and Domestic Buildings
• Theory of Architecture
• Browse content in Art
• Art Subjects and Themes
• History of Art
• Industrial and Commercial Art
• Theory of Art
• Biographical Studies
• Byzantine Studies
• Browse content in Classical Studies
• Classical Philosophy
• Classical Mythology
• Classical History
• Classical Reception
• Classical Numismatics
• Classical Literature
• Classical Art and Architecture
• Classical Oratory and Rhetoric
• Greek and Roman Epigraphy
• Greek and Roman Law
• Greek and Roman Archaeology
• Greek and Roman Papyrology
• Late Antiquity
• Religion in the Ancient World
• Social History
• Digital Humanities
• Browse content in History
• Colonialism and Imperialism
• Diplomatic History
• Environmental History
• Genealogy, Heraldry, Names, and Honours
• Genocide and Ethnic Cleansing
• Historical Geography
• History by Period
• History of Agriculture
• History of Education
• History of Emotions
• History of Gender and Sexuality
• Industrial History
• Intellectual History
• International History
• Labour History
• Legal and Constitutional History
• Local and Family History
• Maritime History
• Military History
• National Liberation and Post-Colonialism
• Oral History
• Political History
• Public History
• Regional and National History
• Revolutions and Rebellions
• Slavery and Abolition of Slavery
• Social and Cultural History
• Theory, Methods, and Historiography
• Urban History
• World History
• Browse content in Language Teaching and Learning
• Language Learning (Specific Skills)
• Language Teaching Theory and Methods
• Browse content in Linguistics
• Applied Linguistics
• Cognitive Linguistics
• Computational Linguistics
• Forensic Linguistics
• Grammar, Syntax and Morphology
• Historical and Diachronic Linguistics
• History of English
• Language Acquisition
• Language Variation
• Language Families
• Language Evolution
• Language Reference
• Lexicography
• Linguistic Theories
• Linguistic Typology
• Linguistic Anthropology
• Phonetics and Phonology
• Psycholinguistics
• Sociolinguistics
• Translation and Interpretation
• Writing Systems
• Browse content in Literature
• Bibliography
• Children's Literature Studies
• Literary Studies (Asian)
• Literary Studies (European)
• Literary Studies (Eco-criticism)
• Literary Studies (Modernism)
• Literary Studies (Romanticism)
• Literary Studies (American)
• Literary Studies - World
• Literary Studies (1500 to 1800)
• Literary Studies (19th Century)
• Literary Studies (20th Century onwards)
• Literary Studies (African American Literature)
• Literary Studies (British and Irish)
• Literary Studies (Early and Medieval)
• Literary Studies (Fiction, Novelists, and Prose Writers)
• Literary Studies (Gender Studies)
• Literary Studies (Graphic Novels)
• Literary Studies (History of the Book)
• Literary Studies (Plays and Playwrights)
• Literary Studies (Poetry and Poets)
• Literary Studies (Postcolonial Literature)
• Literary Studies (Queer Studies)
• Literary Studies (Science Fiction)
• Literary Studies (Travel Literature)
• Literary Studies (War Literature)
• Literary Studies (Women's Writing)
• Literary Theory and Cultural Studies
• Mythology and Folklore
• Shakespeare Studies and Criticism
• Browse content in Media Studies
• Browse content in Music
• Applied Music
• Dance and Music
• Ethics in Music
• Ethnomusicology
• Gender and Sexuality in Music
• Medicine and Music
• Music Cultures
• Music and Religion
• Music and Culture
• Music and Media
• Music Education and Pedagogy
• Music Theory and Analysis
• Musical Scores, Lyrics, and Libretti
• Musical Structures, Styles, and Techniques
• Musicology and Music History
• Performance Practice and Studies
• Race and Ethnicity in Music
• Sound Studies
• Browse content in Performing Arts
• Browse content in Philosophy
• Aesthetics and Philosophy of Art
• Epistemology
• Feminist Philosophy
• History of Western Philosophy
• Metaphysics
• Moral Philosophy
• Non-Western Philosophy
• Philosophy of Science
• Philosophy of Action
• Philosophy of Law
• Philosophy of Religion
• Philosophy of Language
• Philosophy of Mind
• Philosophy of Perception
• Philosophy of Mathematics and Logic
• Practical Ethics
• Social and Political Philosophy
• Browse content in Religion
• Biblical Studies
• Christianity
• East Asian Religions
• History of Religion
• Judaism and Jewish Studies
• Qumran Studies
• Religion and Education
• Religion and Health
• Religion and Politics
• Religion and Science
• Religion and Law
• Religion and Art, Literature, and Music
• Religious Studies
• Browse content in Society and Culture
• Cookery, Food, and Drink
• Cultural Studies
• Customs and Traditions
• Ethical Issues and Debates
• Hobbies, Games, Arts and Crafts
• Natural world, Country Life, and Pets
• Popular Beliefs and Controversial Knowledge
• Sports and Outdoor Recreation
• Technology and Society
• Travel and Holiday
• Visual Culture
• Browse content in Law
• Arbitration
• Browse content in Company and Commercial Law
• Commercial Law
• Company Law
• Browse content in Comparative Law
• Systems of Law
• Competition Law
• Browse content in Constitutional and Administrative Law
• Government Powers
• Judicial Review
• Local Government Law
• Military and Defence Law
• Parliamentary and Legislative Practice
• Construction Law
• Contract Law
• Browse content in Criminal Law
• Criminal Procedure
• Criminal Evidence Law
• Sentencing and Punishment
• Employment and Labour Law
• Environment and Energy Law
• Browse content in Financial Law
• Banking Law
• Insolvency Law
• History of Law
• Human Rights and Immigration
• Intellectual Property Law
• Browse content in International Law
• Private International Law and Conflict of Laws
• Public International Law
• IT and Communications Law
• Jurisprudence and Philosophy of Law
• Law and Politics
• Law and Society
• Browse content in Legal System and Practice
• Courts and Procedure
• Legal Skills and Practice
• Legal System - Costs and Funding
• Primary Sources of Law
• Regulation of Legal Profession
• Medical and Healthcare Law
• Browse content in Policing
• Criminal Investigation and Detection
• Police and Security Services
• Police Procedure and Law
• Police Regional Planning
• Browse content in Property Law
• Personal Property Law
• Restitution
• Study and Revision
• Terrorism and National Security Law
• Browse content in Trusts Law
• Wills and Probate or Succession
• Browse content in Medicine and Health
• Browse content in Allied Health Professions
• Arts Therapies
• Clinical Science
• Dietetics and Nutrition
• Occupational Therapy
• Operating Department Practice
• Physiotherapy
• Radiography
• Speech and Language Therapy
• Browse content in Anaesthetics
• General Anaesthesia
• Browse content in Clinical Medicine
• Acute Medicine
• Cardiovascular Medicine
• Clinical Genetics
• Clinical Pharmacology and Therapeutics
• Dermatology
• Endocrinology and Diabetes
• Gastroenterology
• Genito-urinary Medicine
• Geriatric Medicine
• Infectious Diseases
• Medical Oncology
• Medical Toxicology
• Pain Medicine
• Palliative Medicine
• Rehabilitation Medicine
• Respiratory Medicine and Pulmonology
• Rheumatology
• Sleep Medicine
• Sports and Exercise Medicine
• Clinical Neuroscience
• Community Medical Services
• Critical Care
• Emergency Medicine
• Forensic Medicine
• Haematology
• History of Medicine
• Browse content in Medical Dentistry
• Oral and Maxillofacial Surgery
• Paediatric Dentistry
• Restorative Dentistry and Orthodontics
• Surgical Dentistry
• Medical Ethics
• Browse content in Medical Skills
• Clinical Skills
• Communication Skills
• Nursing Skills
• Surgical Skills
• Medical Statistics and Methodology
• Browse content in Neurology
• Clinical Neurophysiology
• Neuropathology
• Nursing Studies
• Browse content in Obstetrics and Gynaecology
• Gynaecology
• Occupational Medicine
• Ophthalmology
• Otolaryngology (ENT)
• Browse content in Paediatrics
• Neonatology
• Browse content in Pathology
• Chemical Pathology
• Clinical Cytogenetics and Molecular Genetics
• Histopathology
• Medical Microbiology and Virology
• Patient Education and Information
• Browse content in Pharmacology
• Psychopharmacology
• Browse content in Popular Health
• Caring for Others
• Complementary and Alternative Medicine
• Self-help and Personal Development
• Browse content in Preclinical Medicine
• Cell Biology
• Molecular Biology and Genetics
• Reproduction, Growth and Development
• Primary Care
• Professional Development in Medicine
• Browse content in Psychiatry
• Addiction Medicine
• Child and Adolescent Psychiatry
• Forensic Psychiatry
• Learning Disabilities
• Old Age Psychiatry
• Psychotherapy
• Browse content in Public Health and Epidemiology
• Epidemiology
• Public Health
• Browse content in Radiology
• Clinical Radiology
• Interventional Radiology
• Nuclear Medicine
• Radiation Oncology
• Reproductive Medicine
• Browse content in Surgery
• Cardiothoracic Surgery
• Gastro-intestinal and Colorectal Surgery
• General Surgery
• Neurosurgery
• Paediatric Surgery
• Peri-operative Care
• Plastic and Reconstructive Surgery
• Surgical Oncology
• Transplant Surgery
• Trauma and Orthopaedic Surgery
• Vascular Surgery
• Browse content in Science and Mathematics
• Browse content in Biological Sciences
• Aquatic Biology
• Biochemistry
• Bioinformatics and Computational Biology
• Developmental Biology
• Ecology and Conservation
• Evolutionary Biology
• Genetics and Genomics
• Microbiology
• Molecular and Cell Biology
• Natural History
• Plant Sciences and Forestry
• Research Methods in Life Sciences
• Structural Biology
• Systems Biology
• Zoology and Animal Sciences
• Browse content in Chemistry
• Analytical Chemistry
• Computational Chemistry
• Crystallography
• Environmental Chemistry
• Industrial Chemistry
• Inorganic Chemistry
• Materials Chemistry
• Medicinal Chemistry
• Mineralogy and Gems
• Organic Chemistry
• Physical Chemistry
• Polymer Chemistry
• Study and Communication Skills in Chemistry
• Theoretical Chemistry
• Browse content in Computer Science
• Artificial Intelligence
• Computer Architecture and Logic Design
• Game Studies
• Human-Computer Interaction
• Mathematical Theory of Computation
• Programming Languages
• Software Engineering
• Systems Analysis and Design
• Virtual Reality
• Browse content in Computing
• Business Applications
• Computer Security
• Computer Games
• Computer Networking and Communications
• Digital Lifestyle
• Graphical and Digital Media Applications
• Operating Systems
• Browse content in Earth Sciences and Geography
• Atmospheric Sciences
• Environmental Geography
• Geology and the Lithosphere
• Maps and Map-making
• Meteorology and Climatology
• Oceanography and Hydrology
• Palaeontology
• Physical Geography and Topography
• Regional Geography
• Soil Science
• Urban Geography
• Browse content in Engineering and Technology
• Agriculture and Farming
• Biological Engineering
• Civil Engineering, Surveying, and Building
• Electronics and Communications Engineering
• Energy Technology
• Engineering (General)
• Environmental Science, Engineering, and Technology
• History of Engineering and Technology
• Mechanical Engineering and Materials
• Technology of Industrial Chemistry
• Transport Technology and Trades
• Browse content in Environmental Science
• Applied Ecology (Environmental Science)
• Conservation of the Environment (Environmental Science)
• Environmental Sustainability
• Environmentalist Thought and Ideology (Environmental Science)
• Management of Land and Natural Resources (Environmental Science)
• Natural Disasters (Environmental Science)
• Nuclear Issues (Environmental Science)
• Pollution and Threats to the Environment (Environmental Science)
• Social Impact of Environmental Issues (Environmental Science)
• History of Science and Technology
• Browse content in Materials Science
• Ceramics and Glasses
• Composite Materials
• Metals, Alloying, and Corrosion
• Nanotechnology
• Browse content in Mathematics
• Applied Mathematics
• Biomathematics and Statistics
• History of Mathematics
• Mathematical Education
• Mathematical Finance
• Mathematical Analysis
• Numerical and Computational Mathematics
• Probability and Statistics
• Pure Mathematics
• Browse content in Neuroscience
• Cognition and Behavioural Neuroscience
• Development of the Nervous System
• Disorders of the Nervous System
• History of Neuroscience
• Invertebrate Neurobiology
• Molecular and Cellular Systems
• Neuroendocrinology and Autonomic Nervous System
• Neuroscientific Techniques
• Sensory and Motor Systems
• Browse content in Physics
• Astronomy and Astrophysics
• Atomic, Molecular, and Optical Physics
• Biological and Medical Physics
• Classical Mechanics
• Computational Physics
• Condensed Matter Physics
• Electromagnetism, Optics, and Acoustics
• History of Physics
• Mathematical and Statistical Physics
• Measurement Science
• Nuclear Physics
• Particles and Fields
• Plasma Physics
• Quantum Physics
• Relativity and Gravitation
• Semiconductor and Mesoscopic Physics
• Browse content in Psychology
• Affective Sciences
• Clinical Psychology
• Cognitive Neuroscience
• Cognitive Psychology
• Criminal and Forensic Psychology
• Developmental Psychology
• Educational Psychology
• Evolutionary Psychology
• Health Psychology
• History and Systems in Psychology
• Music Psychology
• Neuropsychology
• Organizational Psychology
• Psychological Assessment and Testing
• Psychology of Human-Technology Interaction
• Psychology Professional Development and Training
• Research Methods in Psychology
• Social Psychology
• Browse content in Social Sciences
• Browse content in Anthropology
• Anthropology of Religion
• Human Evolution
• Medical Anthropology
• Physical Anthropology
• Regional Anthropology
• Social and Cultural Anthropology
• Theory and Practice of Anthropology
• Browse content in Business and Management
• Business Strategy
• Business History
• Business Ethics
• Business and Government
• Business and Technology
• Business and the Environment
• Comparative Management
• Corporate Governance
• Corporate Social Responsibility
• Entrepreneurship
• Health Management
• Human Resource Management
• Industrial and Employment Relations
• Industry Studies
• Information and Communication Technologies
• International Business
• Knowledge Management
• Management and Management Techniques
• Operations Management
• Organizational Theory and Behaviour
• Pensions and Pension Management
• Public and Nonprofit Management
• Social Issues in Business and Management
• Strategic Management
• Supply Chain Management
• Browse content in Criminology and Criminal Justice
• Criminal Justice
• Criminology
• Forms of Crime
• International and Comparative Criminology
• Youth Violence and Juvenile Justice
• Development Studies
• Browse content in Economics
• Agricultural, Environmental, and Natural Resource Economics
• Asian Economics
• Behavioural Finance
• Behavioural Economics and Neuroeconomics
• Econometrics and Mathematical Economics
• Economic Systems
• Economic Methodology
• Economic History
• Economic Development and Growth
• Financial Markets
• Financial Institutions and Services
• General Economics and Teaching
• Health, Education, and Welfare
• History of Economic Thought
• International Economics
• Labour and Demographic Economics
• Law and Economics
• Macroeconomics and Monetary Economics
• Microeconomics
• Public Economics
• Urban, Rural, and Regional Economics
• Welfare Economics
• Browse content in Education
• Adult Education and Continuous Learning
• Care and Counselling of Students
• Early Childhood and Elementary Education
• Educational Equipment and Technology
• Educational Strategies and Policy
• Higher and Further Education
• Organization and Management of Education
• Philosophy and Theory of Education
• Schools Studies
• Secondary Education
• Teaching of a Specific Subject
• Teaching of Specific Groups and Special Educational Needs
• Teaching Skills and Techniques
• Browse content in Environment
• Applied Ecology (Social Science)
• Climate Change
• Conservation of the Environment (Social Science)
• Environmentalist Thought and Ideology (Social Science)
• Management of Land and Natural Resources (Social Science)
• Natural Disasters (Environment)
• Pollution and Threats to the Environment (Social Science)
• Social Impact of Environmental Issues (Social Science)
• Sustainability
• Browse content in Human Geography
• Cultural Geography
• Economic Geography
• Political Geography
• Browse content in Interdisciplinary Studies
• Communication Studies
• Museums, Libraries, and Information Sciences
• Browse content in Politics
• African Politics
• Asian Politics
• Chinese Politics
• Comparative Politics
• Conflict Politics
• Elections and Electoral Studies
• Environmental Politics
• Ethnic Politics
• European Union
• Foreign Policy
• Gender and Politics
• Human Rights and Politics
• Indian Politics
• International Relations
• International Organization (Politics)
• Irish Politics
• Latin American Politics
• Middle Eastern Politics
• Political Methodology
• Political Communication
• Political Philosophy
• Political Sociology
• Political Theory
• Political Behaviour
• Political Economy
• Political Institutions
• Politics and Law
• Politics of Development
• Public Administration
• Public Policy
• Qualitative Political Methodology
• Quantitative Political Methodology
• Regional Political Studies
• Russian Politics
• Security Studies
• State and Local Government
• UK Politics
• US Politics
• Browse content in Regional and Area Studies
• African Studies
• Asian Studies
• East Asian Studies
• Japanese Studies
• Latin American Studies
• Middle Eastern Studies
• Native American Studies
• Scottish Studies
• Browse content in Research and Information
• Research Methods
• Browse content in Social Work
• Addictions and Substance Misuse
• Adoption and Fostering
• Care of the Elderly
• Child and Adolescent Social Work
• Couple and Family Social Work
• Direct Practice and Clinical Social Work
• Emergency Services
• Human Behaviour and the Social Environment
• International and Global Issues in Social Work
• Mental and Behavioural Health
• Social Justice and Human Rights
• Social Policy and Advocacy
• Social Work and Crime and Justice
• Social Work Macro Practice
• Social Work Practice Settings
• Social Work Research and Evidence-based Practice
• Welfare and Benefit Systems
• Browse content in Sociology
• Childhood Studies
• Community Development
• Comparative and Historical Sociology
• Disability Studies
• Economic Sociology
• Gender and Sexuality
• Gerontology and Ageing
• Health, Illness, and Medicine
• Marriage and the Family
• Migration Studies
• Occupations, Professions, and Work
• Organizations
• Population and Demography
• Race and Ethnicity
• Social Theory
• Social Movements and Social Change
• Social Research and Statistics
• Social Stratification, Inequality, and Mobility
• Sociology of Religion
• Sociology of Education
• Sport and Leisure
• Urban and Rural Studies
• Browse content in Warfare and Defence
• Defence Strategy, Planning, and Research
• Land Forces and Warfare
• Military Administration
• Military Life and Institutions
• Naval Forces and Warfare
• Other Warfare and Defence Issues
• Peace Studies and Conflict Resolution
• Weapons and Equipment

• < Previous chapter
• Next chapter >

5 Doctrinal Legal Research as a Means of Synthesizing Facts, Thoughts, and Legal Principles

• Published: January 2020
• Cite Icon Cite
• Permissions Icon Permissions

Doctrinal legal research (DLR) is a predominant method employed by various classes of legal researchers. It involves rigorous analysis and creative synthesis of multiple doctrinal strands. Doctrines are central to juridical treatment of concepts. Since legal propositions have roots in economic, social, political, and psychological factors, an inter-disciplinary approach becomes essential. Because of the need to overarch changing values, social mores, and economic factors, doctrinal research collaborates with historical, comparative, analytical, and philosophical methods of research. DLR has a long history and definite procedure. Adoption of required steps systematises DLR. It has received criticism for excessively relying on concepts rather than social inputs; for ignoring the empirical techniques; for concentrating only on court decisions or legal rules. It differs from non-doctrinal legal research in the matter of data, venue of research, and time and money utilised. Because of social character of law there is need for collaboration between DLR and NDLR for positive outcome.

Personal account

• Sign in with email/username & password
• Get email alerts
• Save searches
• Purchase content
• Activate your purchase/trial code
• Add your ORCID iD

Institutional access

Sign in with a library card.

• Sign in with username/password
• Recommend to your librarian
• Institutional account management
• Get help with access

Access to content on Oxford Academic is often provided through institutional subscriptions and purchases. If you are a member of an institution with an active account, you may be able to access content in one of the following ways:

IP based access

Typically, access is provided across an institutional network to a range of IP addresses. This authentication occurs automatically, and it is not possible to sign out of an IP authenticated account.

Choose this option to get remote access when outside your institution. Shibboleth/Open Athens technology is used to provide single sign-on between your institution’s website and Oxford Academic.

• Click Sign in through your institution.
• Select your institution from the list provided, which will take you to your institution's website to sign in.
• When on the institution site, please use the credentials provided by your institution. Do not use an Oxford Academic personal account.
• Following successful sign in, you will be returned to Oxford Academic.

If your institution is not listed or you cannot sign in to your institution’s website, please contact your librarian or administrator.

Enter your library card number to sign in. If you cannot sign in, please contact your librarian.

Society Members

Society member access to a journal is achieved in one of the following ways:

Sign in through society site

Many societies offer single sign-on between the society website and Oxford Academic. If you see ‘Sign in through society site’ in the sign in pane within a journal:

• Click Sign in through society site.
• When on the society site, please use the credentials provided by that society. Do not use an Oxford Academic personal account.

If you do not have a society account or have forgotten your username or password, please contact your society.

Sign in using a personal account

Some societies use Oxford Academic personal accounts to provide access to their members. See below.

A personal account can be used to get email alerts, save searches, purchase content, and activate subscriptions.

Some societies use Oxford Academic personal accounts to provide access to their members.

Viewing your signed in accounts

Click the account icon in the top right to:

• View your signed in personal account and access account management features.
• View the institutional accounts that are providing access.

Signed in but can't access content

Oxford Academic is home to a wide variety of products. The institutional subscription may not cover the content that you are trying to access. If you believe you should have access to that content, please contact your librarian.

For librarians and administrators, your personal account also provides access to institutional account management. Here you will find options to view and activate subscriptions, manage institutional settings and access options, access usage statistics, and more.

Our books are available by subscription or purchase to libraries and institutions.

• About Oxford Academic
• Publish journals with us
• University press partners
• What we publish
• New features  
• Open access
• Rights and permissions
• Accessibility
• Advertising
• Media enquiries
• Oxford University Press
• Oxford Languages
• University of Oxford

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

• Copyright © 2024 Oxford University Press
• Cookie settings
• Cookie policy
• Privacy policy
• Legal notice

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Information

• Author Services

Initiatives

You are accessing a machine-readable page. In order to be human-readable, please install an RSS reader.

All articles published by MDPI are made immediately available worldwide under an open access license. No special permission is required to reuse all or part of the article published by MDPI, including figures and tables. For articles published under an open access Creative Common CC BY license, any part of the article may be reused without permission provided that the original article is clearly cited. For more information, please refer to https://www.mdpi.com/openaccess .

Feature papers represent the most advanced research with significant potential for high impact in the field. A Feature Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for future research directions and describes possible research applications.

Feature papers are submitted upon individual invitation or recommendation by the scientific editors and must receive positive feedback from the reviewers.

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

Original Submission Date Received: .

• Active Journals
• Find a Journal
• Proceedings Series
• For Authors
• For Reviewers
• For Editors
• For Librarians
• For Publishers
• For Societies
• For Conference Organizers
• Open Access Policy
• Institutional Open Access Program
• Special Issues Guidelines
• Editorial Process
• Research and Publication Ethics
• Article Processing Charges
• Testimonials
• Preprints.org
• SciProfiles
• Encyclopedia

Article Menu

• Subscribe SciFeed
• Recommended Articles
• Google Scholar
• on Google Scholar
• Table of Contents

Find support for a specific problem in the support section of our website.

Please let us know what you think of our products and services.

Visit our dedicated information section to learn more about MDPI.

JSmol Viewer

Integration and optimization of multisource electric vehicles: a critical review of hybrid energy systems, topologies, and control algorithms.

1. Introduction

2. hybrid energy storage systems (hesss), 2.1. batteries (bts), 2.2. fuel cells (fcs), 2.3. supercapacitors (scs), 2.4. flywheels (fws), 3. transmotors.

• elec refers to the electrical port;
• ir refers to the inner rotor;
• or refers to the outer rotor.
• ω e l e c is the electrical frequency of the currents applied to the windings;
• n is the number of pole pairs of the transmotor;
• ω i r is the rotating speed of the inner rotor;
• ω o r is the rotating speed of the outer rotor;
• T e l e c is the electrical torque;
• T i r is the inner rotor’s torque;
• T o r is the outer rotor’s torque;
• e i n d is the electromotive force induced in the conductor;
• v is the velocity of the conductor;
• B is the magnetic field;
• l is the length vector of the conductor.
• Scenario A: The vehicle aims to accelerate. When the inner rotor, which is connected to the FW through a gear box, spins faster than the outer rotor that is connected to the drive shaft (DS) of the vehicle, the transmotor’s clutch function engages to transfer kinetic energy from the FW to the drive shaft. Simultaneously, its generator function converts excess kinetic energy from the FW into electrical energy, charging the BT. As a result, the vehicle accelerates using mechanical energy from the FW, enhancing the BT‘s charge. Interestingly, this topology is unique, as it charges the BT instead of draining it during acceleration demands.
• Scenario B: The vehicle also intends to accelerate, but in this scenario, the outer rotor moves faster than the inner rotor. Here, the transmotor’s clutch function aids in managing power transfer from the BT to the drive shaft, and its electric motor function converts electrical energy from the BT into mechanical energy, assisting in drive shaft acceleration. Consequently, the vehicle harnesses additional power from the BT for acceleration.
• Scenario C: The vehicle decelerates, with the outer rotor moving faster than the inner rotor. The transmotor engages its clutch to manage the deceleration process and transfer excess kinetic energy from the drive shaft to the FW. Its generator function then converts this excess kinetic energy into electrical energy, recharging the BT. The outcome is vehicle deceleration accompanied by BT charging.
• Scenario D: The vehicle needs to decelerate, and the inner rotor is spinning faster than the outer rotor. The transmotor’s clutch function engages to manage the power transfer from the BT, providing braking power. Then, the transmotor will work as a generator charging the BT system. The four scenarios are summarized in Table 2 .

4. Multisource EVs

4.1. topologies of hesss, 4.1.1. bevs.

• Passive cascade battery and supercapacitor configuration: In this setup, SCs are connected in parallel with the BT and linked to the motor (denoted as “M” in the following figures), through both a DC/DC converter and a DC/AC converter to enhance the system’s power performance capability, as depicted in Figure 4 a. A bidirectional converter links the SCs to the DC link, controlling the power flow either sourced from or fed into the SCs. Despite significant voltage fluctuations at the SC terminals, the voltage at the DC link is maintained nearly constant due to regulation by the bidirectional converter. However, the BT voltage is equal to the DC link voltage, as there is no control mechanism between the BT and the SC. The current from the BT must both charge the SC and provide power to the load. A major disadvantage of this placement is its inefficiency in utilizing the stored energy in the SC [ 8 , 13 , 26 , 40 , 51 ].

4.1.2. Fuel Cell Electric Vehicles (FCEVs)

• Direct parallel connection/semi-active topology: In this setup, the SC is connected directly to the DC link without a DC/DC converter, while the FC is connected to the DC link with a non-bidirectional DC/DC converter, as depicted in Figure 7 a. This direct connection simplifies the circuitry and control strategies, enhancing cost-effectiveness by eliminating the need for a DC/DC converter and enabling faster response times to power demands. However, this arrangement can lead to a voltage mismatch between the SC and the DC link, particularly as the SoC of the SC changes. There is no precise control of the power flow between the SC and the system, which could lead to instability under varying operational conditions and increased wear, ultimately reducing their lifespans [ 56 , 57 , 58 ].
• Direct parallel connection of fuel cell and battery : In this configuration, shown in Figure 8 a, both the BT and the FC are connected directly to the DC link without any DC/DC converters. Clearly, this setup is the most cost effective, simplest, and easiest to implement in an FCEV. However, the risks associated with backward current flow due to the uncontrollable DC voltage at the DC link, as well as the limitations in controlling power flow, are significant drawbacks that render this topology unsuitable for implementation in an FCEV [ 57 , 58 ]. The issue of backward current flow can be mitigated by using diodes, but this solution reduces the overall efficiency [ 60 ]. Finally, regenerative braking is not feasible with this topology.

5. Energy Management Algorithms for Multisource EVs

5.1. energy management systems (emss).

• Electrical management: Manages the charging and discharging processes to avoid voltage and current inequalities between cells, tailored to the parameters of each energy storage system.
• Thermal management: Ensures the balance of temperature among cells, maintaining the correct operating temperature for all components.
• Safety management: Evaluates sensor outputs and initiates the shutdown of components that are in a high-risk state, such as during a collision [ 51 , 67 ].

5.2. Optimization Control Strategies of Multisource EVs

• Rule-based algorithms;
• Optimization algorithms;
• Artificial intelligence-based algorithms.

5.3. Rule-Based Algorithms

5.3.1. deterministic rules.

• Optimal Working Condition-Based Methods

5.3.2. Fuzzy Logic

• Basic Fuzzy Logic (BFL)

5.4. Optimization-Based Algorithms

5.4.1. online algorithms.

• Equivalent Consumption Minimization Strategy (ECMS)

5.4.2. Offline Algorithms

• Direct Algorithms

5.5. Learning Based

• Reinforcement Learning (RL)

6. Conclusions

Author contributions, conflicts of interest, abbreviations.

• Denton, T. Electric and Hybrid Vehicles ; 711 Third Avenue: New York, NY, USA, 2016. [ Google Scholar ]
• Stephanie Brinley US EV Sales Grew Nearly 52% in 2023. So Why Are Automakers Slowing EV Investments? Available online: https://www.spglobal.com/mobility/en/research-analysis/us-ev-sales-grew-nearly-52-in-2023.html (accessed on 1 August 2024).
• Jerry, A. Madrid Electric and Hybrid Vehicle Battery Technologies: Advancements and Challenges. Int. J. Adv. Res. Sci. Commun. Technol. 2023 , 3 , 803–807. [ Google Scholar ] [ CrossRef ]
• Larminie, J.; Lowry, J. Electric Vehicle Technology Explained , 2nd ed.; John Wiley & Sons: Chichester, UK, 2012; ISBN 9781119942733. [ Google Scholar ]
• Verma, S.; Mishra, S.; Gaur, A.; Chowdhury, S.; Mohapatra, S.; Dwivedi, G.; Verma, P. A Comprehensive Review on Energy Storage in Hybrid Electric Vehicle. J. Traffic Transp. Eng. (Engl. Ed.) 2021 , 8 , 621–637. [ Google Scholar ] [ CrossRef ]
• Xie, Y.; Zhao, X.; Cai, W.; Qi, G.; Wang, Z.; Zhang, Y.; Yang, Y. Design and Optimisation of Oil Injection Pipe Cooling Structure for Permanent Magnet Synchronous Motors in Hybrid Electric Vehicles. IET Electr. Power Appl. 2024 , 18 , 345–355. [ Google Scholar ] [ CrossRef ]
• Bauman, J.; Kazerani, M. A Comparative Study of Fuel-Cell-Battery, Fuel-Cell-Ultracapacitor, and Fuel-Cell-Battery-Ultracapacitor Vehicles. IEEE Trans. Veh. Technol. 2008 , 57 , 760–769. [ Google Scholar ] [ CrossRef ]
• Khaligh, A.; Li, Z. Battery, Ultracapacitor, Fuel Cell, and Hybrid Energy Storage Systems for Electric, Hybrid Electric, Fuel Cell, and Plug-in Hybrid Electric Vehicles: State of the Art. IEEE Trans. Veh. Technol. 2010 , 59 , 2806–2814. [ Google Scholar ] [ CrossRef ]
• Farrokhzad Ershad, N.; Mehrjardi, R.T.; Ehsani, M. Electro-Mechanical EV Powertrain with Reduced Volt-Ampere Rating. IEEE Trans. Veh. Technol. 2019 , 68 , 224–233. [ Google Scholar ] [ CrossRef ]
• Tie, S.F.; Tan, C.W. A Review of Energy Sources and Energy Management System in Electric Vehicles. Renew. Sustain. Energy Rev. 2013 , 20 , 82–102. [ Google Scholar ]
• Salmasi, F.R. Control Strategies for Hybrid Electric Vehicles: Evolution, Classification, Comparison, and Future Trends. IEEE Trans. Veh. Technol. 2007 , 56 , 2393–2404. [ Google Scholar ] [ CrossRef ]
• Doucette, R.T.; McCulloch, M.D. A Comparison of High-Speed Flywheels, Batteries, and Ultracapacitors on the Bases of Cost and Fuel Economy as the Energy Storage System in a Fuel Cell Based Hybrid Electric Vehicle. J. Power Sources 2011 , 196 , 1163–1170. [ Google Scholar ] [ CrossRef ]
• Ju, F.; Zhang, Q.; Deng, W.; Li, J. Review of Structures and Control of Battery-Supercapacitor Hybrid Energy Storage System for Electric Vehicles ; The Institute of Electrical and Electronics Engineers, Inc.: New York, NY, USA, 2014; ISBN 9781479952830. [ Google Scholar ]
• Sulaiman, N.; Hannan, M.A.; Mohamed, A.; Majlan, E.H.; Wan Daud, W.R. A Review on Energy Management System for Fuel Cell Hybrid Electric Vehicle: Issues and Challenges. Renew. Sustain. Energy Rev. 2015 , 52 , 802–814. [ Google Scholar ] [ CrossRef ]
• Hannan, M.A.; Hoque, M.M.; Mohamed, A.; Ayob, A. Review of Energy Storage Systems for Electric Vehicle Applications: Issues and Challenges. Renew. Sustain. Energy Rev. 2017 , 69 , 771–789. [ Google Scholar ] [ CrossRef ]
• Habib, A.K.M.A.; Hasan, M.K.; Mahmud, M.; Motakabber, S.M.A.; Ibrahimya, M.I.; Islam, S. A Review: Energy Storage System and Balancing Circuits for Electric Vehicle Application. IET Power Electron. 2021 , 14 , 1–13. [ Google Scholar ] [ CrossRef ]
• International Energy Agency. Review 2021 Assessing the Effects of Economic Recoveries on Global Energy Demand. and CO2 Emissions in 2021 Global Energy ; International Energy Agency: Paris, France, 2021. [ Google Scholar ]
• Iqbal, M.; Benmouna, A.; Becherif, M.; Mekhilef, S. Survey on Battery Technologies and Modeling Methods for Electric Vehicles. Batteries 2023 , 9 , 185. [ Google Scholar ] [ CrossRef ]
• Piatkowski, P.; Michalska-Pozoga, I.; Szczepanek, M. Fuel Cells in Road Vehicles. Energies 2022 , 15 , 8606. [ Google Scholar ] [ CrossRef ]
• Salado, M.; Gonçalves, R.; Costa, C.M.; Lanceros-Méndez, S. Lithium-Ion Batteries: Electrodes, Separators, and Solid Polymer Electrolytes. In Sustainable Energy Storage in the Scope of Circular Economy: Advanced Materials and Device Design ; John Wiley and Sons Ltd.: Hoboken, NJ, USA, 2023; pp. 43–68. ISBN 9781119817703. [ Google Scholar ]
• Xia, Q.; Ren, Y.; Wang, Z.; Yang, D.; Yan, P.; Wu, Z.; Sun, B.; Feng, Q.; Qian, C. Safety Risk Assessment Method for Thermal Abuse of Lithium-Ion Battery Pack Based on Multiphysics Simulation and Improved Bisection Method. Energy 2023 , 264 , 126228. [ Google Scholar ] [ CrossRef ]
• Kurtulmuş, Z.N.; Karakaya, A. Review of Lithium-Ion, Fuel Cell, Sodium-Beta, Nickel-Based and Metal-Air Battery Technologies Used in Electric Vehicles. Int. J. Energy Appl. Technol. 2023 , 10 , 103–113. [ Google Scholar ] [ CrossRef ]
• Bhuvana, J.; Pandeya, M.; Vishnoi, R. Emerging Battery Technologies for High-Power Electric Vehicles. In Proceedings of the 2024 International Conference on Optimization Computing and Wireless Communication, ICOCWC 2024, Debre Tabor, Ethiopia, 29–30 January 2024; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2024. [ Google Scholar ]
• Khan, M. Innovations in Battery Technology: Enabling the Revolution in Electric Vehicles and Energy Storage. Br. J. Multidiscip. Adv. Stud. 2024 , 5 , 23–41. [ Google Scholar ] [ CrossRef ]
• Lü, X.; Wu, Y.; Lian, J.; Zhang, Y.; Chen, C.; Wang, P.; Meng, L. Energy Management of Hybrid Electric Vehicles: A Review of Energy Optimization of Fuel Cell Hybrid Power System Based on Genetic Algorithm. Energy Convers. Manag. 2020 , 205 , 112474. [ Google Scholar ] [ CrossRef ]
• Meyers, R.A.; Elgowainy, A. Encyclopedia of Sustainability Science and Technology Series Editor-in-Chief: A Volume in the Encyclopedia of Sustainability Science and Technology , 2nd ed.; Electric, Hybrid, and Fuel Cell Vehicles; Springer: Palm Desert, CA, USA, 2021. [ Google Scholar ]
• Deb, N.; Alam, M.Z.; Rahman, T.; Jami, M.S.; Bt Mansor, M.F.; Tajuddin, H.B.A. Design and Analysis of a Fuel Cell and Batteries in Energy Production for Electric Vehicle. Iran. J. Energy Environ. 2023 , 14 , 301–313. [ Google Scholar ] [ CrossRef ]
• De Wolf, D.; Smeers, Y. Comparison of Battery Electric Vehicles and Fuel Cell Vehicles. World Electr. Veh. J. 2023 , 14 , 262. [ Google Scholar ] [ CrossRef ]
• Xu, Z. Hydrogen Fuel-Cell Technology in Electric Vehicles: Current Usage, Materials and Future Applications ; Darcy & Roy Press: Hillsboro, OR, USA, 2022; Volume 2022. [ Google Scholar ]
• Wang, Y.; Leung, D.Y.C.; Xuan, J.; Wang, H. A Review on Unitized Regenerative Fuel Cell Technologies, Part-A: Unitized Regenerative Proton Exchange Membrane Fuel Cells. Renew. Sustain. Energy Rev. 2016 , 65 , 961–977. [ Google Scholar ] [ CrossRef ]
• Sharma, S.; Panwar, A.K.; Tripathi, M.M. Storage Technologies for Electric Vehicles. J. Traffic Transp. Eng. (Engl. Ed.) 2020 , 7 , 340–361. [ Google Scholar ] [ CrossRef ]
• Kularatna, N.; Subasinghage, K.; Gunawardane, K.; Jayananda, D.; Ariyarathna, T. Supercapacitor-Assisted Techniques and Supercapacitor-Assisted Loss Management Concept: New Design Approaches to Change the Roadmap of Power Conversion Systems. Electronics 2021 , 10 , 1697. [ Google Scholar ] [ CrossRef ]
• Şahin, M.E.; Blaabjerg, F. A Hybrid PV-Battery/Supercapacitor System and a Basic Active Power Control Proposal in MATLAB/Simulink. Electronics 2020 , 9 , 129. [ Google Scholar ] [ CrossRef ]
• Makuwatsine, T.T.; Gill, A.; Gupta, S.; Chauhan, S. Supercapacitor and Battery Hybrid Energy Storage System for Electric Vehicle. In Proceedings of the 2023 3rd Asian Conference on Innovation in Technology, ASIANCON 2023, Ravet, IN, India, 25–27 August 2023; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2023. [ Google Scholar ]
• Rajagopal, S.; Pulapparambil Vallikkattil, R.; Mohamed Ibrahim, M.; Velev, D.G. Electrode Materials for Supercapacitors in Hybrid Electric Vehicles: Challenges and Current Progress. Condens. Matter 2022 , 7 , 6. [ Google Scholar ] [ CrossRef ]
• Tundwal, A.; Kumar, H.; Binoj, B.J.; Sharma, R.; Kumar, G.; Kumari, R.; Dhayal, A.; Yadav, A.; Singh, D.; Kumar, P. Developments in Conducting Polymer-, Metal Oxide-, and Carbon Nanotube-Based Composite Electrode Materials for Supercapacitors: A Review. RSC Adv. 2024 , 14 , 9406–9439. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Laadjal, K.; Marques Cardoso, A.J. A Review of Supercapacitors Modeling, SoH, and SoE Estimation Methods: Issues and Challenges. Int. J. Energy Res. 2021 , 45 , 18424–18440. [ Google Scholar ] [ CrossRef ]
• Li, H.; Chu, J.; Sun, S. High-Performance Flywheel Hybrid Powertrain. Sustainability 2022 , 14 , 8076. [ Google Scholar ] [ CrossRef ]
• Amiryar, M.E.; Pullen, K.R.; Nankoo, D. Development of a High-Fidelity Model for an Electrically Driven Energy Storage Flywheel Suitable for Small Scale Residential Applications. Appl. Sci. 2018 , 8 , 453. [ Google Scholar ] [ CrossRef ]
• Ehsani, M.; Singh, K.V.; Bansal, H.O.; Mehrjardi, R.T. State of the Art and Trends in Electric and Hybrid Electric Vehicles. Proc. IEEE 2021 , 109 , 967–984. [ Google Scholar ] [ CrossRef ]
• Lin, Z.; Li, D.; Zou, Y. Energy Efficiency of Lithium-Ion Batteries: Influential Factors and Long-Term Degradation. J. Energy Storage 2023 , 74 , 109386. [ Google Scholar ] [ CrossRef ]
• Holtkamp, M.; Alonso, G. RAQ Issue 179: Energy Storage Using Supercapacitors: How Big Is Big Enough? Analog Devices Inc.: Norwood, MA, USA, 2020; Volume 54. [ Google Scholar ]
• Mehrjardi, R.T.; Ershad, N.F.; Ehsani, M. Transmotor-Flywheel Powertrain Assisted by Ultracapacitor. IEEE Trans. Transp. Electrif. 2022 , 8 , 3686–3695. [ Google Scholar ] [ CrossRef ]
• Tafazzoli Mehrjardi, R.; Ershad, N.F.; Ehsani, M. Transmotor-Based Powertrain for High-Performance Electric Vehicle. IEEE Trans. Transp. Electrif. 2020 , 6 , 1199–1210. [ Google Scholar ] [ CrossRef ]
• Ershad, N.F.; Mehrjardi, R.; Ehsani, M. Development of a Kinetic Energy Recovery System Using an Active Electromagnetic Slip Coupling. IEEE Trans. Transp. Electrif. 2019 , 5 , 456–464. [ Google Scholar ] [ CrossRef ]
• Ershad, N.F.; Mehrjardi, R.T.; Ehsani, M. Efficient Flywheel-Based All-Wheel-Drive Electric Powertrain. IEEE Trans. Ind. Electron. 2021 , 68 , 5661–5671. [ Google Scholar ] [ CrossRef ]
• Raghuwanshi, A.; Ojha, A. An Overview of the Regenerative Braking Technique and Energy Storage Systems in Electric, Hybrid, and Plug-In Hybrid Electric Vehicles. In Proceedings of the 2023 IEEE International Students’ Conference on Electrical, Electronics and Computer Science, SCEECS 2023, Bhopal, India, 18–19 February 2023; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2023. [ Google Scholar ]
• Sayed, K.; Abdel-Khalek, S.; Zakaly, H.M.H.; Aref, M. Energy Management and Control in Multiple Storage Energy Units (Battery–Supercapacitor) of Fuel Cell Electric Vehicles. Materials 2022 , 15 , 8932. [ Google Scholar ] [ CrossRef ]
• Yavasoglu, H.A.; Shi, C.; Gokce, K. Energy Storage Systems for EVs with Two Propulsion Machines. In Proceedings of the2017 IEEE Transportation Electrification Conference and Expo (ITEC), Chicago, IL, USA, 22–24 June 2017; IEEE: Kocaeli, Turkey, 2017. ISBN 9781509039531. [ Google Scholar ]
• Hredzak, B.; Agelidis, V.G.; Jang, M. A Model Predictive Control System for a Hybrid Battery-Ultracapacitor Power Source. IEEE Trans. Power Electron. 2014 , 29 , 1469–1479. [ Google Scholar ] [ CrossRef ]
• Ehsani, M.; Gao, Y.; Longo, S.; Ebrahimi, K. Modern Electric, Hybrid Electric, and Fuel Cell Vehicles , 3rd ed.; CRC Press: Boca Raton, FL, USA, 2018. [ Google Scholar ]
• Dhand, A.; Pullen, K. Analysis of Dual Mode Continuously Variable Transmission for Flywheel Energy Storage Systems. In SAE Technical Papers ; SAE International: Warrendale, PA, USA, 2016; Volume 2016. [ Google Scholar ]
• Dhand, A.; Pullen, K. Analysis of Continuously Variable Transmission for Flywheel Energy Storage Systems in Vehicular Application. Proc. Inst. Mech. Eng. C J. Mech. Eng. Sci. 2015 , 229 , 273–290. [ Google Scholar ] [ CrossRef ]
• Dhand, A.; Pullen, K. Optimal Energy Management for a Flywheel-Assisted Battery Electric Vehicle. Proc. Inst. Mech. Eng. Part D J. Automob. Eng. 2015 , 229 , 1672–1682. [ Google Scholar ] [ CrossRef ]
• Marzougui, H.; Kadri, A.; Bacha, F. Rule-Based Power Sharing Strategy for a Fuel Cell-Supercapacitor Vehicle. In Proceedings of the 2021 IEEE 2nd International Conference on Signal, Control and Communication, SCC 2021, Tunis, Tunisia, 20–22 December 2021; Institute of Electrical and Electronics Engineers Inc.: New York, USA, 2021; pp. 113–118. [ Google Scholar ]
• Li, M.; Yu, P.; Wang, Y.; Sun, Z.; Chen, Z. Topology Comparison and Sensitivity Analysis of Fuel Cell Hybrid Systems for Electric Vehicles. IEEE Trans. Transp. Electrif. 2023 , 9 , 5111–5121. [ Google Scholar ] [ CrossRef ]
• Kasimalla, V.K.R.; Naga Srinivasulu, G.; Velisala, V. A Review on Energy Allocation of Fuel Cell/Battery/Ultracapacitor for Hybrid Electric Vehicles. Int. J. Energy Res. 2018 , 42 , 4263–4283. [ Google Scholar ] [ CrossRef ]
• Yu, P.; Li, M.; Wang, Y.; Chen, Z. Fuel Cell Hybrid Electric Vehicles: A Review of Topologies and Energy Management Strategies. World Electr. Veh. J. 2022 , 13 , 172. [ Google Scholar ] [ CrossRef ]
• Kök, C.; Mert, S.O. Energetic and Exergetic Performance Investigation of Different Topologies for Hybrid Fuel Cell Vehicles. Int. J. Energy Res. 2023 , 2023 , 7165382. [ Google Scholar ] [ CrossRef ]
• Ragab, A.; Marei, M.I.; Mokhtar, M. Comprehensive Study of Fuel Cell Hybrid Electric Vehicles: Classification, Topologies, and Control System Comparisons. Appl. Sci. 2023 , 13 , 13057. [ Google Scholar ] [ CrossRef ]
• Xie, C.; Xu, X.; Bujlo, P.; Shen, D.; Zhao, H.; Quan, S. Fuel Cell and Lithium Iron Phosphate Battery Hybrid Powertrain with an Ultracapacitor Bank Using Direct Parallel Structure. J. Power Sources 2015 , 279 , 487–494. [ Google Scholar ] [ CrossRef ]
• Gao, D.; Jin, Z.; Lu, Q. Energy Management Strategy Based on Fuzzy Logic for a Fuel Cell Hybrid Bus. J. Power Sources 2008 , 185 , 311–317. [ Google Scholar ] [ CrossRef ]
• Kuo, J.K.; Hsieh, H.K. Research of Flywheel System Energy Harvesting Technology for Fuel Cell Hybrid Vehicles. Fuel Cells 2013 , 13 , 1234–1241. [ Google Scholar ] [ CrossRef ]
• Hearn, C.S.; Flynn, M.M.; Lewis, M.C.; Thompson, R.C.; Murphy, B.T.; Longoria, R.G. Low cost flywheel energy storage for a fuel cell powered transit bus. In Proceedings of the 2007 IEEE Vehicle Power and Propulsion Conference, Arlington, TX, USA, 9–12 September 2007. [ Google Scholar ]
• D’Ovidio, G.; Masciovecchio, C.; Rotondale, N. City Bus Powered by Hydrogen Fuel Cell and Flywheel Energy Storage System. In Proceedings of the IEEE International Electric Vehicle Conference, Florence, Italy, 17–19 December 2014; ISBN 9781479960750. [ Google Scholar ]
• D’Ovidio, G.; Masciovecchio, C.; Ometto, A.; Villante, C. On Design of Hybrid Power Unit with Partitioned Fuel-Cell and Flywheel Energy Sorage System for City Transit Buses. In Proceedings of the International Symposium on Power Electronics, Electrical Drives, Automation and Motion, Sorrento, Italy, 24–26 June 2020; ISBN 9781728170190. [ Google Scholar ]
• Rimpas, D.; Kaminaris, S.D.; Aldarraji, I.; Piromalis, D.; Vokas, G.; Papageorgas, P.G.; Tsaramirsis, G. Energy Management and Storage Systems on Electric Vehicles: A Comprehensive Review. Mater. Today Proc. 2022 , 61 , 813–819. [ Google Scholar ] [ CrossRef ]
• Farrokhi, E.; Safari, P.; Ghoreishy, H. A Rule-Based Energy Management Strategy with Current Estimation for Controlling Grid Connected Hybrid Energy Storage System. In Proceedings of the 2023 14th Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2023, 31 January–2 February 2023, 31 January–2 February 2023; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2023. [ Google Scholar ]
• Barhoumi, N.; Marzougui, H.; Bacha, F.; Boukhnifer, M. Energy Management Algorithm of Fuel Cell/Supercapacitor System for Electrical Vehicle. In Proceedings of the 2022 8th International Conference on Control, Decision and Information Technologies, CoDIT 2022, Istanbul, Turkey, 17–20 May 2022; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2022; pp. 1415–1420. [ Google Scholar ]
• Kraa, O.; Boualem, S.; Kermadi, M. Flow-Chart Power Management for Grid-Connected Hybrid System. EEA—Electroteh. Electron. Autom. 2023 , 71 , 75–82. [ Google Scholar ] [ CrossRef ]
• Moulik, B.; Söffker, D. Optimal Rule-Based Power Management for Online, Real-Time Applications in Hevs with Multiple Sources and Objectives: A Review. Energies 2015 , 8 , 9049–9063. [ Google Scholar ] [ CrossRef ]
• Hajji, B.; Mellit, A.; Marco Tina, G.; Rabhi, A.; Launay, J.; Eddine Naimi Editors, S. Proceedings of the 2nd International Conference on Electronic Engineering and Renewable Energy Systems ; Springer: Singapore, 2020. [ Google Scholar ]
• Trovao, J.P.F.; Roux, M.A.; Menard, E.; Dubois, M.R. Energy- and Power-Split Management of Dual Energy Storage System for a Three-Wheel Electric Vehicle. IEEE Trans. Veh. Technol. 2017 , 66 , 5540–5550. [ Google Scholar ] [ CrossRef ]
• Belkhier, Y.; Oubelaid, A.; Shaw, R.N. Hybrid Power Management and Control of Fuel Cells-Battery Energy Storage System in Hybrid Electric Vehicle under Three Different Modes. Energy Storage 2024 , 6 , e51. [ Google Scholar ] [ CrossRef ]
• Omakor, J.; Alzayed, M.; Chaoui, H. Particle Swarm-Optimized Fuzzy Logic Energy Management of Hybrid Energy Storage in Electric Vehicles. Energies 2024 , 17 , 2163. [ Google Scholar ] [ CrossRef ]
• Chen, J.; Xu, C.; Wu, C.; Xu, W. Adaptive Fuzzy Logic Control of Fuel-Cell-Battery Hybrid Systems for Electric Vehicles. IEEE Trans. Ind. Inform. 2018 , 14 , 292–300. [ Google Scholar ] [ CrossRef ]
• Beşkardeş, A.; Hameş, Y.; Kaya, K. A Comprehensive Review on Fuzzy Logic Control Systems for All, Hybrid, and Fuel Cell Electric Vehicles. Soft Comput. 2024 , 28 , 8183–8221. [ Google Scholar ] [ CrossRef ]
• Castaings, A.; Lhomme, W.; Trigui, R.; Bouscayrol, A. Energy Management of a Multi-Source Vehicle by λ-Control. Appl. Sci. 2020 , 10 , 6541. [ Google Scholar ] [ CrossRef ]
• Tang, Y.; Xie, J.; Shen, Y.; Sun, S.; Li, Y. Energy Management Strategy Based on Model Predictive Control-Differential Evolution for Hybrid Energy Storage System in Electric Vehicles. IET Electr. Syst. Transp. 2024 , 2024 , 8840942. [ Google Scholar ] [ CrossRef ]
• Zhao, Y.; Wang, W.; Xiang, C.; Liu, H.; Reza, L. Research and Bench Test of Nonlinear Model Predictive Control-Based Power Allocation Strategy for Hybrid Energy Storage System. IEEE Access 2018 , 6 , 70770–70787. [ Google Scholar ] [ CrossRef ]
• Majeed, M.A.; Khan, M.G.; Asghar, F. Nonlinear Control of Hybrid Energy Storage System for Hybrid Electric Vehicles. Int. Trans. Electr. Energy Syst. 2020 , 30 , e12268. [ Google Scholar ] [ CrossRef ]
• Hu, L.; Tian, Q.; Zou, C.; Huang, J.; Ye, Y.; Wu, X. A Study on Energy Distribution Strategy of Electric Vehicle Hybrid Energy Storage System Considering Driving Style Based on Real Urban Driving Data. Renew. Sustain. Energy Rev. 2022 , 162 , 112416. [ Google Scholar ] [ CrossRef ]
• Cui, Z.; Guo, Z.; Manthiram, A. Irreparable Interphase Chemistry Degradation Induced by Temperature Pulse in Lithium-Ion Batteries. Angew. Chem. Int. Ed. 2023 , 62 , e202313437. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Ahsan, M.B.F.; Mekhilef, S.; Soon, T.K.; Usama, M.; Binti Mubin, M.; Seyedmahmoudian, M.; Stojcevski, A.; Mokhlis, H.; Shrivastava, P.; Alshammari, O. Optimal Sizing and Cost Analysis of Hybrid Energy Storage System for EVs Using Metaheuristic PSO and Firefly Algorithms. Results Eng. 2024 , 23 , 102358. [ Google Scholar ] [ CrossRef ]
• Zheng, C.; Li, W.; Liang, Q. An Energy Management Strategy of Hybrid Energy Storage Systems for Electric Vehicle Applications. IEEE Trans. Sustain. Energy 2018 , 9 , 1880–1888. [ Google Scholar ] [ CrossRef ]
• Intidam, A.; El Fadil, H.; Nady, S.; Benzouina, O.; Koundi, M.; Rachid, K. Nonlinear Optimization Technique for Energy Management of HESS in Fuel Cell Electric Vehicle. In Proceedings of the IFAC-PapersOnLine, Casablanca, Morocco, 29 June–1 July 2022; Elsevier: Amsterdam, The Netherlands, 2022; Volume 55, pp. 426–431. [ Google Scholar ]
• Mounica, V.; Obulesu, Y.P. An Energy Management Scheme for Improving the Fuel Economy of a Fuel Cell/Battery/Supercapacitor-Based Hybrid Electric Vehicle Using the Coyote Optimization Algorithm (COA). Front. Energy Res. 2023 , 11 , 1180531. [ Google Scholar ] [ CrossRef ]
• Li, X.; Li, M.; Habibi, M.; Najaafi, N.; Safarpour, H. Optimization of Hybrid Energy Management System Based on High-Energy Solid-State Lithium Batteries and Reversible Fuel Cells. Energy 2023 , 283 , 128454. [ Google Scholar ] [ CrossRef ]
• Chen, T.C.; Ibrahim Alazzawi, F.J.; Grimaldo Guerrero, J.W.; Chetthamrongchai, P.; Dorofeev, A.; Ismael, A.M.; Al Ayub Ahmed, A.; Akhmadeev, R.; Latipah, A.J.; Esmail Abu Al-Rejal, H.M. Development of Machine Learning Methods in Hybrid Energy Storage Systems in Electric Vehicles. Math. Probl. Eng. 2022 , 2022 , 3693263. [ Google Scholar ] [ CrossRef ]
• Ranjbaran, P.; Ebrahimi, J.; Bakhshai, A.; Jain, P. Reinforcement Learning-Based Approaches to Energy Management of Hybrid Energy Storage Systems in Electric Vehicles. In Proceedings of the International Conference on Power Electronics and Drive Systems, Aalborg, Denmark, 4–8 September 2023; Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2023; Volume 2023. [ Google Scholar ]
• Shuai, Q.; Wang, Y.; Jiang, Z.; Hua, Q. Reinforcement Learning-Based Energy Management for Fuel Cell Electrical Vehicles Considering Fuel Cell Degradation. Energies 2024 , 17 , 1586. [ Google Scholar ] [ CrossRef ]
• Mukhcrjee, N.; Sarkar, S. A Deep Concurrent Learning-Based Robust and Optimal Energy Management Strategy for Hybrid Energy Storage Systems in Plug-in Hybrid Electric Vehicles. In Proceedings of the 2023 IEEE Vehicle Power and Propulsion Conference, VPPC 2023, Milan, Italy, 24–27 October 2023; Proceedings. Institute of Electrical and Electronics Engineers Inc.: New York, NY, USA, 2023. [ Google Scholar ]
• Yavasoglu, H.A.; Tetik, Y.E.; Ozcan, H.G. Neural Network-Based Energy Management of Multi-Source (Battery/UC/FC) Powered Electric Vehicle. Int. J. Energy Res. 2020 , 44 , 12416–12429. [ Google Scholar ] [ CrossRef ]
• Jui, J.J.; Ahmad, M.A.; Molla, M.M.I.; Rashid, M.I.M. Optimal Energy Management Strategies for Hybrid Electric Vehicles: A Recent Survey of Machine Learning Approaches. J. Eng. Res. 2024 , in press. [ Google Scholar ] [ CrossRef ]
• Sun, H.; Tao, F.; Fu, Z.; Gao, A.; Jiao, L. Driving-Behavior-Aware Optimal Energy Management Strategy for Multi-Source Fuel Cell Hybrid Electric Vehicles Based on Adaptive Soft Deep-Reinforcement Learning. IEEE Trans. Intell. Transp. Syst. 2023 , 24 , 4127–4146. [ Google Scholar ] [ CrossRef ]
• Sidharthan Panaparambil, V.; Kashyap, Y.; Vijay Castelino, R. A Review on Hybrid Source Energy Management Strategies for Electric Vehicle. Int. J. Energy Res. 2021 , 45 , 19819–19850. [ Google Scholar ] [ CrossRef ]
• Zhang, Q.; Wang, L.; Li, G.; Liu, Y. A Real-Time Energy Management Control Strategy for Battery and Supercapacitor Hybrid Energy Storage Systems of Pure Electric Vehicles. J. Energy Storage 2020 , 31 , 101721. [ Google Scholar ] [ CrossRef ]
• Li, S.; Hou, Z.; Chu, L.; Jiang, J.; Zhang, Y. A Novel Learning-Based Robust Model Predictive Control Energy Management Strategy for Fuel Cell Electric Vehicles. arXiv 2022 , arXiv:2209.04995. [ Google Scholar ]

Click here to enlarge figure

Share and Cite

Fesakis, N.; Falekas, G.; Palaiologou, I.; Lazaridou, G.E.; Karlis, A. Integration and Optimization of Multisource Electric Vehicles: A Critical Review of Hybrid Energy Systems, Topologies, and Control Algorithms. Energies 2024 , 17 , 4364. https://doi.org/10.3390/en17174364

Fesakis N, Falekas G, Palaiologou I, Lazaridou GE, Karlis A. Integration and Optimization of Multisource Electric Vehicles: A Critical Review of Hybrid Energy Systems, Topologies, and Control Algorithms. Energies . 2024; 17(17):4364. https://doi.org/10.3390/en17174364

Fesakis, Nikolaos, Georgios Falekas, Ilias Palaiologou, Georgia Eirini Lazaridou, and Athanasios Karlis. 2024. "Integration and Optimization of Multisource Electric Vehicles: A Critical Review of Hybrid Energy Systems, Topologies, and Control Algorithms" Energies 17, no. 17: 4364. https://doi.org/10.3390/en17174364

Article Metrics

Article access statistics, further information, mdpi initiatives, follow mdpi.

Subscribe to receive issue release notifications and newsletters from MDPI journals