The theoretical literature review helps to 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. Should I provide subheadings and other background information, such as definitions and/or a history?
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. Use the exercise of reviewing the literature to examine how authors in your discipline or area of interest have composed their literature review sections.
Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the primary studies.
Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally that become part of the lore of field.
A literature review may consist of simply a summary of key sources, but in the social sciences, a literature review 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.
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 make summary claims of the sort found in systematic reviews [see below].
A literature review surveys books, scholarly articles, and any other sources relevant to a particular issue, area of research, or theory, and by so doing, provides a description, summary, and critical evaluation of these works in relation to the research problem being investigated.
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 within a larger field of study.