A literature review surveys scholarly articles, books and other sources relevant to a particular issue, area of research, or theory, and by so doing, providing a description, summary, and critical evaluation of these works. Literature reviews are designed to provide an overview of sources you have explored while researching a particular topic and to demonstrate to your readers how your research fits into the larger field of study.
A literature review may consist of a simple summary of key sources, but it usually has an organizational pattern and combines both summary and synthesis, often within specific conceptual categories. A summary is a recap of the important information of the source, but a synthesis is a re-organization, or a reshuffling, of that information in a way that informs how you are planning to investigate a research problem. The analytical features of a literature review might:
Give a new interpretation of old material or combine new with old interpretations,
Trace the intellectual progression of the field, including major debates,
Depending on the situation, evaluate the sources and advise the reader on the most pertinent or relevant, or
Usually in the conclusion of a literature review, identify where gaps exist in how a problem has been researched to date.
The purpose of a literature review is to:
Place each work in the context of its contribution to the understanding of the research problem being studied,
Describe the relationship of each work to the others under consideration,
Identify new ways to interpret, and shed light on any gaps in previous research,
Resolve conflicts amongst seemingly contradictory previous studies,
Identify areas of prior scholarship to prevent duplication of effort,
Point the way in fulfilling a need for additional research, and
Locate your own research within the context of existing literature.
Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper. 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination. Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques. Los Angeles, CA: SAGE, 2011; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students. 2nd ed. Los Angeles, CA: SAGE, 2012.
It is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the original studies. Third, there are the perceptions, conclusions, opinions, and interpretations that are shared informally that become part of the lore of field. In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews. Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are a number of approaches you could adopt depending upon the type of analysis underpinning your study.
Types of Literature Reviews
This form examines literature selectively in order to support or refute an argument, deeply imbedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to making summary claims of the sort found in systematic reviews.
Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication.
Few things rest in isolation from historical precedent. Historical reviews are focused on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.
A review does not always focus on what someone said [content], but how they said it [method of analysis]. This approach provides a framework of understanding at different levels (i.e. those of theory, substantive fields, research approaches and data collection and analysis techniques), enables researchers to draw on a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection and data analysis, and helps highlight many ethical issues which we should be aware of and consider as we go through our study.
This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyze data from the studies that are included in the review. Typically, it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?"
The purpose of this form is to concretely examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review helps establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.
Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper. 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination. Thousand Oaks, CA: Sage Publications, 1998; Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147.
I. Thinking About Your Literature Review
The structure of a literature review should include the following:
An overview of the subject, issue or theory under consideration, along with the objectives of the literature review,
Division of works under review into themes or categories (e.g., works that support a particular position, those against, and those offering alternative approaches entirely),
An explanation of how each work is similar to and how it varies from the others,
Conclusions as to which pieces are best considered in their argument, are most convincing of their opinions, and make the greatest contribution to the understanding and development of their area of research
The critical evaluation of each work should consider:
Provenance: What are the author's credentials? Are the author's arguments supported by evidence (e.g., primary historical material, case studies, narratives, statistics, recent scientific findings)?
Objectivity: Is the author's perspective even-handed or prejudicial? Is contrary data considered or is certain pertinent information ignored to prove the author's point?
Persuasiveness: Which of the author's theses are most/least convincing?
Value: Are the author's arguments and conclusions convincing? Does the work ultimately contribute in any significant way to an understanding of the subject?
II. Development of the Literature Review
Problem formulation -- which topic or field is being examined and what are its component issues?
Literature search -- finding materials relevant to the subject being explored.
Data evaluation -- determining which literature makes a significant contribution to the understanding of the topic.
Analysis and interpretation -- discussing the findings and conclusions of pertinent literature.
Consider the following issues before writing the literature review:
If your assignment is not very specific about what form your literature review should take, seek clarification from your professor by asking these questions:
Roughly how many sources should I include?
What types of sources should I review (books, journal articles, websites)?
Should I summarize, synthesize, or critique your sources by discussing a common theme or issue?
Should I evaluate the sources?
Should I provide subheadings and other background information, such as definitions and/or a history?
Use the exercise of reviewing the literature to examine how authors in your discipline or area of interest have composed their literature reviews. Read them to get a sense of the types of themes you might want to look for in your own research or ways to organize your final review. The bibliography or reference section of sources you've already read are also excellent entry points into your own research.
Narrow the Topic
The narrower your topic, the easier it will be to limit the number of sources you need to read in order to obtain a good survey of relevant resources. Your professor will probably not expect you to read everything that's available about the topic, but you'll make your job easier if you first limit scope of the research problem. A good strategy is to begin by searching the HOMER catalog for books about the topic and review their contents for chapters that focus on more specific issues. You can also review the subject indexes of books to find references to specific issues that can serve as the focus of your research. For example, a book surveying the history of the Israeli-Palestinian conflict may include a chapter on the role Egypt has played in mediating the conflict.
Consider Whether Your Sources are Current
Some disciplines require that you use information that is as current as possible. This is very common in the sciences where research conducted only two years ago could be obsolete. However, when writing a review in the social sciences, a survey of the history of the literature may be what is needed because what is important is how perspectives have changed over the years or within a certain time period. Try sorting through some other current bibliographies or literature reviews in the field to get a sense of what your discipline expects. You can also use this method to consider what is considered by scholars to be a "hot topic" and what is not.
III. Ways to Organize Your Literature Review
If your review follows the chronological method, you could write about the materials according to when they were published. This approach should only be followed if a clear path of research building on previous research can be identified and that these trends follow a clear chronological order of development. For example, a literature review that focuses on continuing research about the emergence of German economic power after the fall of the Soviet Union.
Order your sources by publication chronology, then, only if the order demonstrates a more important trend. For instance, you could order a review of literature on environmental studies of brown fields if the progression revealed, for example, a change in the soil collection practices of the researchers who wrote and/or conducted the studies.
Thematic (“conceptual categories”)
Thematic reviews of literature are organized around a topic or issue, rather than the progression of time. However, progression of time may still be an important factor in a thematic review. For example, a review of the Internet’s impact on American presidential politics could focus on the development of online political satire. While the study focuses on one topic, the Internet’s impact on American presidential politics, it will still be organized chronologically reflecting technological developments in media. The only difference here between a "chronological" and a "thematic" approach is what is emphasized the most: the role of the Internet in presidential politics. Note however that more authentic thematic reviews tend to break away from chronological order. A review organized in this manner would shift between time periods within each section according to the point made.
A methodological approach focuses on the methods utilized by the researcher. For the Internet in American presidential politics project, one methodological approach would be to look at cultural differences between the portrayal of American presidents on American, British, and French websites. Or the review might focus on the fundraising impact of the Internet on a particular political party. A methodological scope will influence either the types of documents in the review or the way in which these documents are discussed.
Other Sections of Your Literature Review
Once you've decided on the organizational method for your literature review, the sections you need to include in the paper should be easy to figure out because they arise from your organizational strategy. In other words, a chronological review would have subsections for each vital time period; a thematic review would have subtopics based upon factors that relate to the theme or issue. However, sometimes you may need to add additional sections that are necessary for your study, but do not fit in the organizational strategy of the body. What other sections you include in the body is up to you but include only what is necessary for the reader to locate your study within the larger scholarship framework.
Here are examples of other sections you may need to include depending on the type of review you write:
Current Situation: information necessary to understand the topic or focus of the literature review.
History: the chronological progression of the field, the literature, or an idea that is necessary to understand the literature review, if the body of the literature review is not already a chronology.
Selection Methods: the criteria you used to select (and perhaps exclude) sources in your literature review. For instance, you might explain that your review includes only peer-reviewed articles and journals.
Standards: the way in which you present your information.
Questions for Further Research: What questions about the field have the review sparked? How will you further your research as a result of the review?
IV. Writing Your Literature Review
Once you've settled on how to organize your literature review, you're ready to write each section. When writing your review, keep in mind these issues.
A literature review in this sense is just like any other academic research paper. Your interpretation of the available sources must be backed up with evidence to show that what you are saying is valid.
Select only the most important points in each source to highlight in the review. The type of information you choose to mention should relate directly to the research problem, whether it is thematic, methodological, or chronological.
Use Quotes Sparingly
Some short quotes are okay if you want to emphasize a point, or if what the author said just cannot be rewritten in your own words. Sometimes you may need to quote certain terms that were coined by the author, not common knowledge, or taken directly from the study. Do not use extensive quotes as a substitute for your own summary and interpretation of the literature.
Summarize and Synthesize
Remember to summarize and synthesize your sources within each paragraph as well as throughout the review. Recapitulate important features of a research study, but then synthesize it by rephrasing the study's significance and relating it to their own work.
Keep Your Own Voice
While the literature review presents others' ideas, your voice (the writer's) should remain front and center. For example, weave references to other sources into what you are writing but maintain your own voice by starting and ending the paragraph with your own ideas and wording.
Use Caution When Paraphrasing
When paraphrasing a source that is not your own, be sure to represent the author's information or opinions accurately and in your own words. Even when paraphrasing an author’s work, you still must provide a citation to that work.
V. Common Mistakes to Avoid
These are the most common mistakes made in reviewing social science research literature.
Sources in your literature review do not clearly relate to the research problem;
You do not take sufficient time to define and identify the most relevant sources to use in the literature review related to the research problem;
Relies exclusively on secondary analytical sources rather than including relevant primary research studies or data;
Uncritically accepts another researcher's findings and interpretations as valid, rather than examining critically all aspects of the research design and analysis;
Does not describe the search procedures that were used in the literature review;
Reports isolated statistical results rather than synthesizing them in chi-squared or meta-analytic methods; and,
Only includes research that validates assumptions and does not consider contrary findings and alternative interpretations found in the literature.
Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper. 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination. Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques. Los Angeles, CA: London : SAGE, 2011; Literature Review Handout. Online Writing Center. Liberty University; Literature Reviews. The Writing Center. University of North Carolina; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students. 2nd ed. Los Angeles, CA: SAGE, 2012; Randolph, Justus J. “A Guide to Writing the Dissertation Literature Review." Practical Assessment, Research, and Evaluation. vol. 14, June 2009; Taylor, Dena. The Literature Review: A Few Tips On Conducting It. University College Writing Centre. University of Toronto; Writing a Literature Review. Academic Skills Centre. University of Canberra.
Break Out of Your Disciplinary Box!
Thinking in an interdisciplinary way about a research problem can be a rewarding exercise in applying new ideas, theories, or concepts to an old problem. For example, what might cultural anthropologists say about the continuing conflict in the Middle East? In what ways might geographers view the need for better distribution of social service agencies in large cities than how social workers might study the issue? You don’t want to substitute a thorough review of core research literature in your discipline for studies conducted in other fields of study. However, particularly in the social sciences, thinking about research problems from multiple vectors is a key strategy for finding new solutions. Consult with a librarian about identifying research databases in other disciplines; almost every field of study has at least one comprehensive database devoted to indexing its research literature.
Don't Just Review for Content!
While conducting a review of the literature, maximize the time you devote to writing this part of your paper by thinking broadly about what you should be looking for and evaluating. Review not just what scholars are saying, but how are they saying it. Some questions to ask:
How are they organizing their ideas?
What methods have they used to study the problem?
What theories have been used to explain, predict, or understand their research problem?
What sources have they cited to support their conclusions?
How have they used non-textual elements [e.g., charts, graphs, figures, etc.] to illustrate key points?
When you begin to write your literature review section, you'll be glad you dug deeper into how the research was constructed because it lays a foundation for developing more substantial analysis and interpretation of the research problem.
Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination. Thousand Oaks, CA: Sage Publications, 1998.
When Do I Know I Can Stop Looking and Move On?
Here are several strategies you can utilize to assess whether you've adequately reviewed the literature:
Look for repeating patterns in the research findings. If the same thing is being said, just by different people, then this likely demonstrates that the research problem has hit a conceptual dead end. At this point consider: Does your study extend current research? Does it forge a new path? Or does it merely add more of the same thing being said?
Look at sources the authors cite in their work. If you begin to see the same researchers cited again and again, then this is often an indication that no new ideas have been introduced in addressing the research question.
Search Google Scholar to identify who has subsequently cited leading scholars already identified in your literature review. This is called citation tracking and there are a number of sources that can help you identify who has cited whom, particularly scholars from outside of your discipline. If the same authors are being cited again and again, this may indicate no new literature has been written on the topic.