A literature review looks at key published material (scholarly articles, books, pamphlets, etc.) on a particular issue, area of research, or theory and provides not only a summary of the source, but also a critical evaluation. Each source is summarized, synthesized, and often evaluated. More than a mere summary of the sources, it highlights what is and is not known, identifies controversy surrounding a topic, formulates questions that need further research, linking the known literature to how your research adds to the larger field of study.
A literature review:
Primary source materials are original research papers written by the experimenter (hint: look for purpose, method, and results in the abstract). A literature review should look at primary source materials.
Secondary source materials generally summarize original research papers written by others. Examples of secondary source materials are review articles, or a description of a treatment in a textbook. Secondary source materials can lead to relevant primary source materials and provide an example of a literature review to examine.
Tertiary source materials systematically analyze or critically review scientific papers. A meta-analysis is an example of a tertiary source material.
Systematic reviews are literature reviews structured by explicit and auditable protocol. They contain:
Meta-analyses are systematic reviews which use a quantitative way of statistically summarizing and comparing the results of the studies reviewed.
Argumentative Review: literature supports or opposes an argument, assumption, or problem established within the literature
Integrative Review: a review that synthesizes the literature such that new perspectives on the topic are introduced.
Historical Review: looks at research throughout a time period, examining trends, evolution, developments--often pointing to future direction for research.
Methodological Review: reviews the method of analyses used in studies--can highlight problems, ethical issues to be aware of in research to be conducted.
Theoretical Review: looks at theories surrounding a concept/issue/phenomena establishing current thinking, degree of investigation regarding the theories, relationships between them, shortcomings, or emerging research problems unanswered by current theories.