Literature Review

Focus

The focus is the basic unit of information that the reviewer extracts from the literature. Reviews most commonly focus on research outcomes, drawing conclusions of the form of “The research shows X” or “These studies find X whereas other studies find Y.” Although research outcomes are most common, other foci are possible. Some reviews focus on research methods, for example, considering how many studies in a field use longitudinal designs. Literature reviews can also focus on theories, such as what theoretical explanations are commonly used within a field or attempts to integrate multiple theoretical perspectives. Finally, literature reviews can focus on typical practices within a field, for instance, on what sort of interventions are used in clinical literature or on the type of data analyses conducted within an area of empirical research.

Goals

Common goals include integrating literature by drawing generalizations (e.g., concluding the strength of an effect from several studies), resolving conflicts (e.g., why an effect is found in some studies but not others), or drawing links across separate fields (e.g., demonstrating that two lines of research are investigating a common phenomenon). Another goal of a literature review might be to identify central issues, such as unresolved questions or next steps for future research. Finally, some reviews have the goal of criticism; although this goal might sound unsavory, it is important for scientific fields to be evaluated critically and have shortcomings noted.

Perspective

Literature reviews also vary in terms of perspective, with some attempting to represent the literature neutrally and others arguing for a position. Although few reviews fall entirely on one end of this dimension or the other, it is useful for readers to consider this perspective when evaluating a review and for writers to consider their own perspective.

Coverage

Coverage refers to the amount of literature on which the review is based. At one extreme of this dimension is exhaustive coverage, which uses all available literature. A similar approach is the exhaustive review with selective citation, in which the reviewer uses all available literature to draw conclusions but cites only a sample of this literature when writing the review. Moving along this dimension, a review can be representative, such that the reviewer bases conclusions on and cites a subset of the existing literature believed to be similar to the larger body of work. Finally, at the far end of this continuum is the literature review of most central works.

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