Evidence Synthesis Service

This decision tree from Cornell University Library can help you determine which type of review is right for your research. You may also want to read the article below by Grant and Booth (2009) to learn about the different types of reviews. 

Literature Review/Narrative Review

• Broad term refers to reviews with a wide scope that examine recent or current literature
• Does not follow established methodology or reporting guidelines
• Search does not need to be comprehensive or exhaustive 
• Critical appraisal is not necessary 
• A good choice for reviewing literature without following defined parameters and on a shorter time frame

Systematic Review

• Seeks to answer a clearly defined research question formulated using a preexisting framework, ex: PICO
• Follows a standard/published methodology 
• Comprehensive and exhaustive searching is required to find all scholarly research on the topic, including both traditionally published and gray literature
• Conducted in an unbiased and reproducible manner 
• Must include critical appraisal of the literature 
• Literature is synthesized in both narrative and tabular formats. 
• Typically take 12-18 months to complete 

Meta-Analysis

• Should follow the methodology of a systematic review 
• Literature is synthesized using a statistical technique for combining the findings from disparate quantitative studies

• Uses statistical methods /software to objectively evaluate, synthesize, and summarize results

Scoping Review

• Seeks to address a broader research question, set of questions, and/or identify gaps in research 
• Follows a standard/published methodology 
• Comprehensive and exhaustive searching is required to find all scholarly research on the topic, including both traditionally published and gray literature
• Conducted in an unbiased and reproducible manner 
• May critically appraise literature but does not seek to synthesize or analyze data in the same manner as a systematic review
• May take longer to complete than a systematic review 

Rapid Review

• Applies systematic review methodology within a time-constrained setting 
• Employs methodological "shortcuts" at the risk of introducing bias
• Useful for addressing issues needing quick decisions
• Shorter time-frame than a systematic review 

Umbrella Review

• Seeks to review other systematic reviews on a particular topic
• Follows a standard/published methodology 
• Often requires a broader question than is typical for a traditional systematic review
• Comprehensive and exhaustive searching is required to find all evidence syntheses on a topic
• Conducted in an unbiased and reproducible manner
• May or may not include a meta-analysis 
• Useful for when there are competing interventions to consider