This guide is designed to help evidence synthesis teams navigate their way through synthesis projects. Those new to this methodology may wish to peruse the entire guide, while those with some experience may only need to visit specific sections of the guide.

The side tabs provide a map of the guide contents; each tab's page will dive into more detail about that process. Much of the detailed guide content will focus on systematic reviews given the current popularity of that review type.

Please note, this guide's contents is subject to regular updates.

Please let Uta Hussong-Christian know if you have questions or have suggestions for the guide.

You may already recognize some evidence synthesis types such as systematic reviews or scoping reviews or even traditional narrative literature reviews. These are very different review types but are all gathered under the evidence synthesis definition. So how is evidence synthesis defined if it can look so different across projects?

The LATITUDES Network defines evidence synthesis as the

"systematic and rigorous approach to gather, analyse, and integrate available research evidence on a specific topic or research question."

Siddaway et al. (2019) further clarify the difference between reviewing the literature and literature reviews/evidence syntheses.

"Reviewing literature involves selectively discussing the literature on a particular topic to make the argument that a new study will make a new and/or important contribution to knowledge. In contrast, literature reviews [evidence syntheses] make up a distinct research design and type of article in their own right. Rather than selectively reviewing relevant literature to make a flowing rationale for a study's existence, they provide a comprehensive synthesis of the available evidence to allow the researcher to draw broad and robust conclusions."

This gathering and analyzing, integrating and conclusion-making is usually done to support decision-making, to create policy/best practices, or to inform understanding.

There are an increasingly large number of synthesis types, many of which are named as some kind of "review." The graphic below presents the evidence synthesis / review types categorized into seven families.

Credit: Birkic, V., Celeste, T., & Cochrane, L. (2020). Graphic illustrating review families. University of Melbourne Library. Based on Sutton et al. (2019). Available from: https://unimelb.libguides.com/whichreview/home. Licensed under CC-BY-ND.

References:

• Siddaway, A. P., Wood, A. M., & Hedges, L. V. (2019). How to do a systematic review: A best practice guide for conducting and reporting narrative reviews, meta-analyses, and meta-syntheses. Annual Review of Psychology, 70(1), 747–770. https://doi.org/10.1146/annurev-psych-010418-102803