What is a literature review?

Not to be confused with a book review, a literature review surveys scholarly articles, books and other sources (e.g. dissertations, conference proceedings) relevant to a particular issue, area of research, or theory, providing a description, summary, and critical evaluation of each work. The purpose is to offer an overview of significant literature published on a topic.

A literature review may constitute an essential chapter of a thesis or dissertation, or may be a self-contained review of writings on a subject. In either case, its purpose is to:

• Place each work in the context of its contribution to the understanding of the subject under review
• 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 forward for further research
• Place one's original work (in the case of theses or dissertations) in the context of existing literature

The literature review itself, however, does not present new primary scholarship.

Similar to primary research, development of the literature review often follows four stages:

1. Problem formulation—which topic or field is being examined and what are its component issues?
2. Literature search—finding materials relevant to the subject being explored
3. Data evaluation—determining which literature makes a significant contribution to the understanding of the topic
4. Analysis and interpretation—discussing the findings and conclusions of pertinent literature

Literature reviews can comprise the following elements:

• An overview of the subject, issue or theory under consideration, along with the objectives of the literature review
• Division of works under review into categories (e.g. those in support of a particular position, those against, and those offering alternative theses entirely)
• 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

In assessing each resource (e.g., article, book chapter) you collect as part of your research, 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?

• What is already known about the area of study? 
• What are the characteristics of the key concepts or the main factors or variables?
• What are the relationships between these key concepts, factors, or variables?
• What are the existing theories?
• What are the inconsistencies or other shortcomings in our knowledge and understanding?
• Why study (further) the research problem?
• What contribution can your study be expected to make?