Literature review is a brief summary and evaluation of several sources discussing one question in detail. A literature review can be a self-contained unit or a preface for further research. As an important part of term papers, courseworks and dissertations, a literature review gives rationale for the choice of topic and it points out at the importance and potential value of findings and their practical application.
Types of sources
As a comprehensive review of a question, literature review contains different sources, including books, articles, web pages and other printed and digital resources[i]. The main principles for selecting resources include:
- Conclusions related to the subject matter (both supporting or disapproving the hypothesis);
- The year of publication;
- Authority of resource and researcher.
Based on reputable sources, literature review includes conflicting views on the problem, which allow analyzing the problem in its complexity.
The following are the main goals of a quality literature review:
- Offer a comprehensive view of the problem, shedding light on it from different perspectives.
- Point out at the gap in the existing literature, which requires further research.
- Give rationale for further research.
Steps of literature analysis
- Formulating a specific research question and narrowing it down.
- Defining the type and main focus of literature review. Literature review can prioritize either issues under analysis or methods used by researchers.
- What types of resources could answer the question most effectively? (year of publication, medium and research method).
- Defining the gaps in the existing literature.
- Analyzing the factors which might potentially create bias in researchers.
- Synthesizing the findings in a comprehensive review.
Structuring and formatting the review
Literature review should not be confused with an annotated bibliography (the latter is a list of sources, referenced according to the rules of a certain citation style and author’s brief comments on them). A literature review has the logical structure similar to that of an essay – an introduction, several paragraphs of the main body and conclusion.
The introduction of the literature review defines the scope of the study. Giving some general information on the background of the study, the introduction includes the main research question. Just like any other academic paper, literature review contains a thesis statement which is usually placed at the end of the introduction.
The main body paragraphs include the author’s major points supported by the quotes from the chosen sources. Importantly, these paragraphs consist mainly of the points made in the previous studies, but united into a whole by means of the author’s own comments. The main body includes contradicting points, which illustrate the different sides of the issue and investigate the problem in-depth to avoid the bias. An important part of the main body discusses the gap in the existing literature and the underestimated areas which require further research. If the literature review is not a self-contained unit, but a part of a bigger research project, it should give rationale for the choice of the research question and methods. Every point in the main body can be supported by one or several sources, separated by semicolons. If several sources have the same information on a certain question, a literature review can put them all in one place.
E.g. A wide range of studies revealed that optimism can have positive effects on individual’s health (Smith, 2009; Brown, 1998; Doe, 2013.)
The conclusion briefly repeats what has already been said in the introduction part, summarizing the main findings and conclusions achieved from the collected materials. The conclusion of a literature review serves as a bridge for the study that follows.
The literature review has a bibliography page, formatted according to the rules of the chosen citation style.
Literature review models
One of the most important steps in writing a literature review is to systematize sources, instead of simply commenting on random sources.
The following are the major types of literature reviews and the most common classification criteria:
Argumentative review is probably the most common type, which is generally used in academic studies. The main purpose of this type of review is to collect arguments, which defend or disapprove a certain point. It is used to defend or refute a deeply embedded assumption or an untraditional point of view.
Historical review places study in a historical context, analyzing the sources, which have been created within a given period of time. This type of research traces the first mentions of the phenomena in literature and then views their evolution in the historical context.
Methodological review shifts the emphasis from research findings to the methods used by researchers. It focuses on the approaches to data collection and analysis at different levels. Instead of discussing “what somebody said”, this type of review focuses on “how somebody said it”.
Theoretical review examines the theory that has been accumulated regarding a certain issue or phenomenon. The researchers establish the relationships between the existing theories and identify to what extent the available studies have investigated the questions under analysis.
According to another classification, the following are the main types of literature reviews:
- Chronological review puts the sources according to the year of their publication. This approach is most effective for tracking the evolution of a certain issue or phenomenon.
- Thematic review groups sources according to the main conclusions made by the scholars. This method focuses on the findings regardless of the date of publication and medium.