Evidence Synthesis

Critically evaluates research in a specific area - its effectiveness and quality;

Typically results in a hypothesis or model rather than an answer to a question

No formal quality appraisal required;

Evaluation is based on the contribution of each source

Incorporates significant analysis using criteria such as strengths, weaknesses, or validity of cited sources;

Identify level of significance, contribution of sources to an overall concept, or derive new theory

A generic term;

Provides a broad overview of a research area or describes literature on a topic to summarize what has been accomplished or identify gaps. Not comprehensive in nature

Comprehensive search not required;

No formal criteria for selecting relevant resources

Map out and classify quality and quantity of existing studies on a topic;

Identifies gaps and provides directions for future research

Formal quality appraisal is required;

Use appraisal to determine inclusion/exclusion of studies, overall quality of studies included, and sensitivity analyses

Requires homogeneity of included studies for analyses to take place;

Statistical analysis of effect size

Synthesize qualitative and quantitative data to develop overarching conclusions;

Typically uses systematic review, comprehensive search methods

Formal quality appraisal is required;

Either use one appraisal tool (MMAT) or separate appraisal tools with comparable criteria to combine for final synthesis

Graphs, tables and narrative;

Goal is synthesizing qualitative and quantitative information

Integrate and compare results from qualitative studies;

Aim is to identify frequently occurring themes or constructs within and/or across studies

Comprehensiveness varies;

May use selective sampling only

Thematic analysis;

May include conceptual models

An expedited collection, assessment and synthesis of studies on a topic to inform policy or practice;

Uses abbreviated (and transparently reported) elements of systematic review methods adapted for a shorter timeline

Formal quality appraisal is required;

Use a time-limited formal appraisal method

Provide an initial exploratory analysis of nature, size, and scope of research on a broad (or multiple related) topic/s not yet examined;

Identify what is known on a topic and directions for future research

Comprehensive and exhaustive search;

Typically includes grey literature

Describe the quantity, quality, size, scope and types of available literature on a topic;

Often leads to future systematic reviews

Focuses on recently published literature to assess current issues
Contrasts with retrospective or current approaches;

Highlights new ideas, gaps or points to future research

Identify and synthesize research on a focused topic;

Uses pre-established, replicable methods for search, appraisal, and synthesis of literature

Formal quality appraisal is required;

Use formal critical appraisal methods to determine the inclusion/exclusion of studies and quality of studies included

A comprehensive search, analysis, and synthesis of material from diverse sources;

Typically seeks to answer a broad question and provide best evidence

Describes most cases in which graduate students conduct an evidence synthesis;

Uses abbreviated (and transparently reported) elements of systematic review methods adapted for a shorter timeline

May include quality appraisal;

May use a time-limited formal appraisal method

Define what is known, unknown, or uncertain about a topic;

Acknowledges procedural limitations

A systematic review of systematic reviews;

Compiles and synthesizes evidence from multiple systematic reviews on a broad topic in which there are multiple differing conclusions / summaries

Comprehensive and exhaustive search is required;

Search looks for systematic reviews and other evidence synthesis, not primary studies

Formal quality appraisal is required;

Appraisal method evaluates quality of studies within each review as well as the overall systematic review/evidence synthesis