Ross Woods, rev. 2018, '20-'25
With thanks to Μιchαel Jοnes, Stephen Whιteheαd, Yunlοk Lee, Βαrry Tse, Jοse Sοαres Αugustο, & Μαrcια J. Βαtes.
A literature review is an integrated analysis of what is already known about your topic. It is usually limited to published information, and sometimes within a certain time period. It normally organizes material into an outline that is easy for readers to follow, and contains summaries with critique or interpretation. It might give a new interpretation of old material, combine new and old interpretations, or trace the progression of the field, including the major debates. Some earlier work may be seminal in nature, providing a rich historical understanding of the topic, making it much more meaningful and interesting.
It will present the key theory(s) informing the study and also offer a critical analysis of competing theories, explaining why a particular theory has been chosen to inform your research.
Literature reviews are usually an early part of a research document, such as a dissertation, thesis, or article for a research journal.
There is no specific rule about how long (or how many words) a literature review must be in a dissertation, because the criteria is really its thoroughness in dealing with the topic. A short review might be adequate for some topics, while a very long review might be inadequate for other topics. However, as a guess at what you might expect, the literature review in a Masters thesis of 20,000 might be about 5,000 words, and it is often from 30 to 50 pages for a PhD. Journal articles usually have strict word limits, so writers must select a limited number of only the most significant and relevant items. In some insitututions, a literature reivew may comprise a whole Masters thesis.
The literature review has two main purposes. First, it gives an up-to-date picture of current research and thinking relevant to your topic and a fair evaluation of the main ideas. This helps to ensure that your research builds on current research and that your research does not unnecessarily repeat work that has already been done. Second, it should justify your core research question and any sub-questions you have. All relevant aspects of the research question should normally appear in the literature review.
Don't treat it as an unhelpful, onerous chore. First, ask questions and look for answers in order to learn something new about your topic. You might even change your views completely. Second, careful treatment of the details is part of being thorough; learning to do so is part of the degree requirements. Third, the better you perceive the current state of knowledge on the topic, the better your research can be.
Your literature review shows:
* With thanks to Μαriα Sτεfαnιdι.
The literature review benefits you in many other ways:
(By the way, literature reviews are also good assignments by themselves. If you have been given the task of writing a literature review as an undergraduate essay, it will most likely be specified as an essay of between 1,500 words and 2,500 words, but the number of items probably won’t be specified.)
Find three or four dissertations on topics similar to yours. The literature reviews are easy to find because they are put in a separate chapter in most dissertations. (Look near the front; it's usually about chapter 2 or 3.) Many journal articles also contain literature reviews.
perfect. They are finished products, and you won't immediately see how they were written.
Before you start, find out what your supervisor expects or allows. This can vary greatly from field to field.
Your literature review should normally include the theory and concepts behind the topic, including critiques, and empirical literature that has produced concrete evidence related to the topic.
Different fields (and different institutions) have different views on the kinds of literature that may be reviewed. In some fields, researchers recognize research only when it has been published in a reputable journal, so they try to identify the leading edge in the journal literature. Other fields, however, are not so narrow and permit or even require other kinds of primary and secondary sources. For example, monographs may be essential.
Across disciplines, examiners expect literature reviews to demonstrate several core competencies. Researchers must show that they have read widely and understand the central debates in their field. They should distinguish between strong, influential work and studies with limited scope or impact. Most importantly, they must identify gaps or problems in the literature that justify the current research and position their study within an existing academic conversation.
Effective critique also requires balance. Researchers should remain critical without becoming dismissive, and confident without sounding dogmatic. Critique targets the work, not the author, and it always relies on clear justification rather than assertion.
Some institutions assume that research frontiers progress rapidly, so they specify that articles must be published within a certain time, for example, within the last three or five years. Having said that, it depends on the topic. I suggest that students should include older writings if they are are still useful and helpful. Standard works
might be quite old but are still very influential and frequently discussed.
Many institutions allow older items and do not specify that articles must be recent. This prevents research from going in circles. Some topics have become unfashionable but later come back into fashion. Some problems were adequately resolved in the past, and researchers might re-consider those solutions. However, researchers also need to make sure that they also use newer sources to make sure they consider any recent developments.
All PhD programs have the same answer: “You need to be exhaustive; the search is is not complete until all relevant documents have been reviewed.” However, a few programs specify a minimum number to promote thoroughness.
It depends on how much has been written, when it was written, and the size and complexity of the topic. If a huge amount has been written recently, you should ask your supervisor whether you should narrow the topic. If your literature review is part of a dissertation, then it needs to be comprehensive and exhaustive. In other words, it is not complete until all relevant documents have been reviewed.
However, different institutions and departments have different definitions of “exhaustive.”
closed access).
How does your supervisor or institution view these different kinds of sources?
standard works.
See alsosource, so that it appears in your list of references.
Wikipedia articles are strictly forbidden, even though the information is generally correct and up to date. However, the footnotes contain links to external supporting sources that might be useful and might also lead to other sources.
The reasons for not allowing Wikipedia articles are as follows:
After that, supervisors have different views, which are usually informed by the specific field or topic of research. You should normally follow your supervisor's advice. Examples of different views are as follows:
Different kinds of sources have different levels of value in research:
There are two main kinds of journals:
Journal articles are often relatively short, and they can be quite recent because they take less time to be published than books. The best journals are all referreed, that is, independent reviewers have approved them before publication.
One kind of article is the research article, which are usually from 4,000-6,000 words and are narrowly focussed on a particular topic. They usually have very specialized relevance, so many articles in the same field will not be relevant to your particular research topic. The other kind of article is the book review; reviewers write short articles reviewing new books published in the specialized field of the journal.
But there is no literature on my topic
What if you do not find any literature on your topic? In a very few cases, nothing has ever been published that is clearly and directly relevant to your topic. Usually, however, much more has been published than students think, and their main difficulties are finding it and seeing how it is relevant.
In these cases, the best practice is usually to review the literature in the next door
subjects, that is, those closely related to the topic that do not impinge upon it. The point of the review is to argue that nothing or very little has been written directly on the topic, usually called a gap in the literature
. What little there is should be closely examined. I call this Long Bridge
strategy for literature reviews. Your task is to build a long bridge between indirectly relevant literature and the topic. Perhaps you feel that are in a unique situation or your topic seems so creative and new.
Consider three kinds of cases:
An early stage in almost all research projects is to do your reading and keep a set of useful notes on what you read.
Writing a long literature review is much easier and less overwhelming when you have a good method. It reduces some complicated tasks to simpler steps, so that you can put your effort into the tasks that require more thought. Instead of immediately trying to write a literature review, it is a much easier to write an annotated bibliography first as a separate stage.
An annotated bibliography is simply a set of organized notes from a reading project on a particular topic or issue with your evaluation of each source. It is then put into a form that others can read:
Your annotated bibliography should show the role and effects of recent research in the field. It is a way of getting ahead start by learning as much as you can from what has already been written. That way, your research project will build on the work of others rather than repeat it. This also gives a firm theoretical basis for your research.
Look at the page on doing an internet search. For a literature review, do most of your search in several databases of research articles, for example, Google Scholar and Core. (A general search of the internet will gather lots of non-research materials of little value.)
When you get a relevant and helpful paper:
Write a brief introduction explaining your purpose. This will most likely be to explore a topic or issue of some kind and say why it is important. You might need to specify the boundaries of the topic. One or two paragraphs is usually enough for an essay.
As an annotated bibliography, the body of your text is the full biblographical details of each source, followed by your comments on each one.
It is adequate to put your items in alphabetical order of the authors last names, just like a normal bibliography. If it helps you to better organize your notes, you can arrange them under section headings for each topic, with the entries under each topic in alphabetical order.
At the end, write a conclusion so your readers know what you concluded. You should mention general patterns, trends, or themes that you can see in the literature. Present your conclusions in an advanced a state as you can justify from the literature. The conclusion should show that you have achieved the purpose that you stated in the introduction.
A book review is a short article that tells readers about a book and gives a fair evaluation of its main ideas. Most academic and professional journals contain reviews of new books that may interest their readers. The purpose is usually to update readers on new ideas in their field. Authors often submit books in the hope of a favorable review, so that they will sell more copies. Lecturers sometimes ask students to write book reviews to assess their understanding of particular books.
A book review normally has the following parts:
Another way of expressing this is the MEAL Plan, which can be a helpful way to construct paragraphs when writing literature reviews:
The MEAL plan is helpful but might not always be appropriate. For example, if several articles say almost the same thing, it might be better to report and comment on them together.
Adapted from Wαlden Acαdemic Guides Link, which adapted it from Duke University's Thοmpsοn Writing Prοogrαm (n.d.) "Paragraphing: The MEAL plan." Link
Then type it up for presentation according to your institution's style guide. Check the layout and proofread your typing, grammar, and language style.
___________
1. Based on “Working Backwards: Moving Past Brain Freeze and Writing Your Problem Statement.” Moliver, Nina. (Unpublished paper.)
2. With thanks to Bαrbαrα Pαvεy.
For more information:
• More reading
• On annotated bibliographies, see Purdue OWL (http://owl.english.purdue.edu/owl/resource/614/01/)
• On annotated bibliographies and making it into a literature review see this link.
The annotations
are your comments on sources relating to your topic. For each source, briefly report the main points or ideas, because you cannot presume that your readers can already know that information. Then say or cleary imply why it’s relevant (and perhaps even unique). Make sure you include in-text references to every source you use so that you don’t plagiarise anything.
Some aspects of critique relate to individual items (books, journal articles) while other aspects relate to whole bodies of literature.
In a thesis or dissertation, a literature review should do more than only summarize existing research. It positions the researcher in an ongoing scholarly conversation. To achieve this, the review must evaluate, interpret, and question the literature rather than merely report it. Critique provides the means to do so. It allows the researcher to explain what the literature does well, where it falls short, and how the present study contributes something new.
Critique forms the backbone of a strong literature review. By engaging critically with theory, methods, evidence, context, and application, researchers demonstrate command of their field and justify their contribution to it.
Critique does not mean finding fault for its own sake. Much published research appears in reputable journals and has already undergone rigorous review. Errors may be rare, but limitations, assumptions, and unresolved questions are still common. A strong literature review engages critically with both individual studies and bodies of work, identifying patterns, tensions, and gaps that shape the field.
Good critique rests on a small number of consistent principles.
When reviewing sources, focus on elements that help resolve your research problem or shape your conclusions. These include strengths, unique features, assumptions, inconsistencies, logical gaps, and implications. The aim is not to catalogue every flaw, but to select issues that matter for your study.
Identifying gaps in the literature often provides the most important justification for a thesis or dissertation. Gaps may appear when researchers overlook certain topics, populations, variables, or perspectives, or when they leave key questions unresolved.
A statement of the research gap is normally included in the introduction of a work of research, because it helps justify a new work of research. However, it can also be necessary to identify other gaps when writing the literature review.
Theoretical critique examines the ideas and assumptions that structure a field of research. It asks which theories dominate the literature, how scholars define key concepts, and whether those definitions remain consistent across studies.
Theoretical critique examines the ideas, conceptual frameworks, and underlying assumptions that shape a field of research and its body of literature. This form of critique pays attention to which theories dominate a field and explores the reasons for their prominence. It also evaluates whether key concepts are clearly defined or whether they are used inconsistently across studies.
In addition, theoretical critique considers whether prevailing assumptions may be outdated, biased, or too narrowly constructed to account for the complexity of the phenomena under investigation. By addressing these issues, the reviewer can highlight both the strengths and the limitations of the theoretical foundations that guide existing research. For example:
Many studies in the field rely heavily on rational choice theory, which assumes that actors behave in an optimal and calculating manner. While this approach has provided a coherent framework for explaining decision-making, it tends to overlook affective and cultural influences. Such influences have been emphasized in more recent sociological models, suggesting that exclusive reliance on rational choice theory may limit the explanatory power of the literature.
Methodological critique focuses on how researchers have designed and conducted their studies. It evaluates research designs, sampling strategies, data collection tools, and analytical techniques.
This type of critique examines the choice of research design, such as whether studies adopt qualitative or quantitative approaches, or whether they rely on cross-sectional or longitudinal data. It also considers issues related to sample size, sampling strategies, and the representativeness of study populations. In addition, methodological critique evaluates the suitability and validity of data collection instruments, as well as the appropriateness of the analytical techniques used to interpret the data.
Check for bias. In confirmation bias, researchers tend to over-value evidence that supports their beliefs, and to disregard other evidence. They can also slant their analyses and findings to find what they wanted to find. Check for other kinds of bias. Some research reports are more tact than fact; they aim to suit funders, current paradigms, or institutional wishes. Some might be deliberately vague ore evasive in order to protect commercially valuable information.
Through this examination, the reviewer can assess the overall rigor and reliability of the research methods employed in the literature. For instance:
Although survey methods dominate much of the existing research, many studies depend on convenience samples. This limits the generalizability of their findings, as the results may not accurately reflect the broader population of interest.
Evidence-based critique assesses whether data support the conclusions researchers draw. It examines the strength, consistency, and reliability of empirical findings. This approach examines whether researchers’ conclusions are adequately supported by the data they report. It also considers any inconsistencies or contradictions across different studies, as well as the extent to which the researcher generalized findings beyond what the evidence can reasonably justify. By focusing on the evidentiary basis of existing research, this form of critique helps to identify how robust and reliable the reported conclusions are. For example:
Although several studies report a positive relationship between the variables under investigation, the observed effect sizes are often small and, in many cases, statistically insignificant. These patterns raise questions about the robustness of the claimed association and suggest that the strength of the evidence may be weaker than the conclusions imply.
Contextual critique looks at where, when, and for whom research applies. It examines the circumstances under which research is produced and the settings to which its findings apply.
It examines cultural, geographic, historical, institutional, and political factors and contexts that may limit or influence the scope of existing studies. It also explores how institutional or political conditions shape research questions, methodologies, and interpretations. In addition, contextual critique assesses whether the literature adequately represents diverse populations or whether it overlooks marginalized groups and non-Western perspectives. Through this lens, the reviewer can evaluate the extent to which research findings are transferable across different contexts. For example:
“Much of the existing research is grounded in North American settings. As a result, the applicability of these findings to developing economies remains insufficiently explored, raising concerns about the broader relevance of the literature.
Comparative critique involves comparing studies to each other rather than evaluating them in isolation, and identifies areas of agreement and disagreement. This approach focuses on identifying patterns of agreement and disagreement across the literature, including conflicting results among studies. It also considers how differences in definitions, methodological choices, or sample characteristics may account for divergent findings. By systematically comparing studies, the reviewer can clarify areas of consensus as well as ongoing debates within the field. For example:
Qualitative studies often place greater emphasis on experiential factors, whereas quantitative research tends to prioritize structural variables. These differing emphases can lead to contrasting interpretations of the same phenomenon, highlighting how methodological and conceptual choices shape research conclusions.
In applied disciplines, critique often focuses on practical relevance. This form of critique examines whether findings translate effectively into real-world settings, and is most common in applied disciplines such as education, health, policy, and business.
This form of critique examines whether studies demonstrate clear practical relevance or whether their applicability is limited to controlled or ideal conditions. It also assesses the strength of the connection between theoretical models and practical implementation, as well as the degree to which researchers acknowledge potential challenges in applying their findings. By addressing these issues, the reviewer can evaluate how useful the literature is for informing practice. For example:
Although an intervention may appear promising in controlled research environments, relatively few studies consider its feasibility in resource-constrained settings. This omission raises concerns about whether the proposed approaches can be effectively implemented beyond experimental contexts.
Some fields in academia have fads and cycles. No matter how important something is, it can go out of style very quickly when no more interesting research emerges or a trendier fad starts to emerge. Some things go in cycles when someone starts to promote an old idea by giving it a new name and definition; it is then treated as if it were a new discovery.
Some forms of political correctness can be trendy for a while and are typically the work of well-meaning persons fighting social justice battles. Ideological assumptions can get dragged into the research process and get magically transformed into “confirmed conclusions.” This rather curious phenomenon has several causes:
• Renaming ideological assumptions as “topics of current interest”
• Renaming bodies of ideology as conceptual or theoretical frameworks
• Circular logic.
how toinformation that might inform or justify your own methodology later on, and give references. This includes methods of analyzing data and data collection tools that you might use with little or no modification.
Cf. also ...or
See also ...comment.
With thanks to Ηumε Jερhcοττ and Sαgnικ Gυhα.
If you have already written an annotated bibliography, converting it to a literature review is mainly a fairly simple editing task, although it still requires some serious thought
You need to develop an outline and decide on section headings that will make sense to your readers. Annotated bibliographies normally put items in the alphabetical order of authors, which is not very helpful for a literature review.
You now have an annotated bibliography that might look like a chaotic mix of different ideas. You now need to turn into a literature review. Your goal is to put the contents into a neat, easy-to-understand order, in language that flows. You want your readers to be able to enjoy reading something that is informative and flows well but still accurately represents the contents.
In essense, you need to group the same ideas together under the main ideas, so that each main idea will become a major section in the outline. Then you need to create outlines for each major section.
To create an outline, find a specific method that works for you. The method you choose is irrelevant as long as it results in an outline that makes sense for your topic and to your readers:
At least one outline will emerge, even if you don't see it at first; you might even have multiple options from which to choose. Besides, you can change it later on if you come to a better understanding of your topic.
If possible, the outline should take the shape of a funnel, starting with the broad concepts and progressing logically to the specific research question or hypothesis.* However, outlines can take various forms, and many researchers need to combine these different kinds of outlines:
Strategy 1: History of ideas
Tell the story. The easiest and most logical literature review to read is a history of main ideas, showing how they follow along in sequence and to some extent flow from one to another. The historical approach allows you to trace the origins and development of major ideas, and indicate the false starts and the unexpected insights. This kind of review picks up on trends, assumptions, and watersheds. Watch for developments that happened simultaneously; they tend to mess up the simple linear structure. Be careful not to miss out major developments that are outside your normal field of reading.
Strategy 2: Author by author
A common approach is to consider the works of major writers one by one. This is useful when their specific ideas are directly relevant to your topic, their works are watersheds, or when writers don't fit into categories very neatly.
Strategy 3: Shape of the literature
Discuss the areas in which literature has been written, and when trends dictated that much would be written and when little or nothing would be written. The library stacks will give a rough idea, although familiarity with issues and major writers is necessary to do a good review. It includes mention of especially significant writings that spurred a great deal of other literature to be written. The great strength of this approach is that you can mention whole bodies of literature, describe their general characteristics and assumptions, and give specific examples. This is very appropriate when the literature is massive and the whole is more important than individual parts. (Don't be caught out; there are times when you need to treat each author as having unique ideas that must be addressed individually.)
Strategy 4: Integration
You might be reviewing very different sources from different schools of thought, but you are showing that they are all saying the similar things, are based on similar assumptions, or responding to similar kinds of problems. Your task it then to pull them together into one coherent, overarching theory.
Strategy 5: Spaghetti
Perhaps the most difficult is the case in which a great deal has been written directly upon the topic. You feel like you are finding a path through a tightly knit pile of spaghetti. The way to do it is to divide the literature into groupings according to history, assumptions, or methodology. You can then use the body of literature
approach.
* With thanks to Μassimο Sρinella
You might find that new topics emerge and you need to improve the outline to cope with the new topics. Don't be afraid to make the changes even if they are radical. Although perhaps frustrating for you, it is a sign of progress because you have learned something new.
Here's why. Creating and modifying an outline is itself an analytical process; you identify which ideas are the most important and which are the subordinate or peripheral. The challenge is to present them in an order that helps your readers.
You will probably go through several drafts of your outline before it is ready to show your supervisor. When you think it is ready, present it to your supervisor as a one-page list of section headings and subheadings to ask for advice and to approve your direction. Later on, you might change the outline and some of those headings as you revise successive drafts. Just check that the changes are improvements and that your supervisor agrees.
Then, do some editing:
The preliminary literature review will be included in your proposal, and, ultimately, will be the basis of the literature review in the final dissertation.