Unless otherwise noted, this guide was adapted from Cornell University's "A Guide to Evidence Synthesis"
At Northwestern University Libraries, we offer general consultations regarding evidence synthesis projects, including literature reviews and systematic reviews. This includes:
If the project requires more long-term support, let us know. We may be able to provide additional assistance such as developing and reviewing search strings. Depending on the level of support provided, the researcher may need to provide acknowledgment of the librarian in the final publication.
If you'd like to set up a consultation, complete the Evidence Synthesis Consultation Request form.
Evidence synthesis refers to any method of identifying, selecting, and combining results from multiple studies. Systematic reviews and literature reviews are two methods of identifying and providing summaries of existing literature on a particular topic. They are quite different in scope and practice.
|Traditional Literature Review||Systematic Review|
|Definition||Qualitatively summarizes evidence on a topic using informal or subjective methods to collect and interpret studies.||Methodically and systematically identifies all literature on a well-formulated research topic, including published and unpublished studies.|
|Goals||To provide a summary or overview of a topic||To provide evidence for practice and policy-making, and to identify gaps in research|
|Question||Topics may be broad in scope; the goal of the review may be to place one's own research within the existing body of knowledge, or to gather information that supports a particular viewpoint.||Starts with a well-defined research question to be answered by the review. Reviews are conducted with the aim of finding all existing evidence in an unbiased, transparent, and reproducible way.|
|Timeline||Weeks or months||12-18 months|
|Synthesis of existing research||Conclusions are more qualitative and may not be based on study quality.||Bases conclusion on quality of the studies and provide recommendations for practice or to address knowledge gaps.|
Adapted from Kysh, L. (2013). What’s in a name? The difference between a systematic review and a literature review and why it matters. [Poster].Retrieved from http://dx.doi.org/10.6084/m9.figshare.766364. Licensed under CC-BY.
Types of evidence synthesis include:
Literature (Narrative) Review
Scoping Review or Evidence Map