TimelyScholarFree Tools › Evidence Gap Map Generator
Build an interactive evidence and gap map (EGM) from your coded studies: a matrix of interventions and outcomes in which bubbles show how many studies exist in each cell, coloured by study design or confidence, with the empty cells marking the gaps.
FreeNo account neededYour data stays in your browser
Select a cell to see its studies. On small screens, scroll the map sideways.
The evidence and gap map includes 18 studies across 6 intervention and 6 outcome categories. 15 of 36 cells contain evidence and 21 (58%) contain no studies. 10 cells have primary studies but no systematic review.
A study coded to several interventions or outcomes appears in each matching cell, so cell counts can add up to more than the number of studies; the row and column totals count each study once. Empty cells show where no studies were found, not that an intervention does not work.
One row per study with its intervention(s), outcome(s) and, optionally, design, confidence rating and a filter such as region.
List every intervention and outcome category so that categories with no studies still appear as gaps.
Filter the map, select a cell to see its studies, then download the figure and a CSV of cell counts.
An evidence and gap map (EGM) is a systematic evidence synthesis product that displays the available evidence relevant to a research question. It is usually drawn as a matrix with intervention categories as rows and outcomes as columns; bubbles in each cell show the studies coded to that combination, with larger bubbles for more studies and colours for study type or confidence in the findings.
EGMs are used to see where evidence is concentrated, to find gaps that need new primary research, and to identify clusters of studies that are ready for a systematic review. Unlike a systematic review, a map describes what evidence exists rather than what it shows about effectiveness.
A systematic review answers a focused question about effects and usually pools or synthesises results. An evidence gap map covers a broader question and shows where studies exist and where they are missing, without synthesising their findings.
Most maps use interventions as rows and outcomes as columns. Other pairings work too, such as interventions against regions, to show the geographical spread of evidence.
No. An empty cell means no eligible studies were found for that combination. It is a gap in the evidence, not evidence of no effect.
Code each included study against a pre-specified framework of intervention and outcome categories, ideally by two people independently, as in a systematic review. A study can be coded to several categories; separate them with semicolons.