Literature Review
Literature Review is a comprehensive survey of the works published in a particular field of study or line of research, usually over a specific period of time, in the form of an in-depth, critical bibliographic essay or annotated list in which attention is drawn to the most significant works.
Also, we can define a literature review as the collected body of scholarly works related to a topic:
- Summarizes and analyzes previous research relevant to a topic
- Includes scholarly books and articles published in academic journals
- Can be an specific scholarly paper or a section in a research paper
The objective of a Literature Review is to find previous published scholarly works relevant to an specific topic
- Help gather ideas or information
- Keep up to date in current trends and findings
- Help develop new questions
A literature review is important because it:
- Explains the background of research on a topic.
- Demonstrates why a topic is significant to a subject area.
- Helps focus your own research questions or problems
- Discovers relationships between research studies/ideas.
- Suggests unexplored ideas or populations
- Identifies major themes, concepts, and researchers on a topic.
- Tests assumptions; may help counter preconceived ideas and remove unconscious bias.
- Identifies critical gaps, points of disagreement, or potentially flawed methodology or theoretical approaches.
- Indicates potential directions for future research.
All content in this section is from Literature Review Research from Old Dominion University
Keep in mind the following, a literature review is NOT:
Not an essay
Not an annotated bibliography in which you summarize each article that you have reviewed. A literature review goes beyond basic summarizing to focus on the critical analysis of the reviewed works and their relationship to your research question.
Not a research paper where you select resources to support one side of an issue versus another. A lit review should explain and consider all sides of an argument in order to avoid bias, and areas of agreement and disagreement should be highlighted.
A literature review serves several purposes. For example, it
- provides thorough knowledge of previous studies; introduces seminal works.
- helps focus one’s own research topic.
- identifies a conceptual framework for one’s own research questions or problems; indicates potential directions for future research.
- suggests previously unused or underused methodologies, designs, quantitative and qualitative strategies.
- identifies gaps in previous studies; identifies flawed methodologies and/or theoretical approaches; avoids replication of mistakes.
- helps the researcher avoid repetition of earlier research.
- suggests unexplored populations.
- determines whether past studies agree or disagree; identifies controversy in the literature.
- tests assumptions; may help counter preconceived ideas and remove unconscious bias.
As Kennedy (2007) notes*, 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, opinion, 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 several approaches to how they can be done, depending upon the type of analysis underpinning your study. Listed below are definitions of types of literature reviews:
Argumentative Review
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 to make summary claims of the sort found in systematic reviews.
Integrative Review
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.
Historical Review
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.
Methodological Review
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.
Systematic Review
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 analyse 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?"
Theoretical Review
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 help 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.
* Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147.
All content in this section is from The Literature Review created by Dr. Robert Larabee USC
Robinson, P. and Lowe, J. (2015), Literature reviews vs systematic reviews. Australian and New Zealand Journal of Public Health, 39: 103-103. doi:10.1111/1753-6405.12393
What's in the name? The difference between a Systematic Review and a Literature Review, and why it matters. By Lynn Kysh from University of Southern California
Systematic review or meta-analysis?
A systematic review answers a defined research question by collecting and summarizing all empirical evidence that fits pre-specified eligibility criteria.
A meta-analysis is the use of statistical methods to summarize the results of these studies.
Systematic reviews, just like other research articles, can be of varying quality. They are a significant piece of work (the Centre for Reviews and Dissemination at York estimates that a team will take 9-24 months), and to be useful to other researchers and practitioners they should have:
- clearly stated objectives with pre-defined eligibility criteria for studies
- explicit, reproducible methodology
- a systematic search that attempts to identify all studies
- assessment of the validity of the findings of the included studies (e.g. risk of bias)
- systematic presentation, and synthesis, of the characteristics and findings of the included studies
Not all systematic reviews contain meta-analysis.
Meta-analysis is the use of statistical methods to summarize the results of independent studies. By combining information from all relevant studies, meta-analysis can provide more precise estimates of the effects of health care than those derived from the individual studies included within a review. More information on meta-analyses can be found in Cochrane Handbook, Chapter 9.
A meta-analysis goes beyond critique and integration and conducts secondary statistical analysis on the outcomes of similar studies. It is a systematic review that uses quantitative methods to synthesize and summarize the results.
An advantage of a meta-analysis is the ability to be completely objective in evaluating research findings. Not all topics, however, have sufficient research evidence to allow a meta-analysis to be conducted. In that case, an integrative review is an appropriate strategy.