A literature review summarizes, synthesizes, and evaluates existing research on a broader topic or question.
Unlike a systematic review, a literature review does not always follow a predefined, reproducible process for identifying and selecting studies. Instead, authors may choose research that helps explain major themes, debates, findings, theories, or developments in a field.
Literature reviews are common across medicine, psychology, education, social science, humanities, engineering, and many other academic disciplines.
How do literature reviews work?
Researchers gather and evaluate existing publications related to a topic, then organize the findings into a coherent synthesis or narrative overview.
A literature review may involve:
Identifying relevant research on a topic
Summarizing findings from multiple sources
Comparing different theories, methods, or conclusions
Organizing research into themes or areas of debate
Identifying conflicting or inconclusive findings
Highlighting gaps, limitations, or unresolved questions
Describing how knowledge on a topic has developed over time
Suggesting directions for future research
For example, researchers might review existing work on the effects of social media on mental health, summarize approaches to renewable energy storage, or compare theories about how people learn.
Strengths of literature reviews
Literature reviews can:
Provide a broad overview of a research area
Bring together findings from many sources
Explain major themes, theories, and debates
Synthesize different perspectives or findings across the literature
Help readers understand how a field has developed
Identify gaps or areas that need further research
Provide useful context for new research questions
Literature reviews can be especially helpful when a reader wants to understand the broader research landscape around a topic and what questions remain unresolved.
Limitations of literature reviews
Because literature reviews do not always use a systematic search and selection process, the studies included may depend more heavily on the authors’ judgment.
Relevant research may be missed, and the review may be more vulnerable to selection bias or differences in how authors interpret the literature.
The rigor of literature reviews can vary depending on how studies are identified, evaluated, and synthesized. The conclusions also depend on the quality and scope of the research being reviewed, and the review may become outdated as new studies are published.