Evidence gap maps: an innovative tool for seeing what we know and don’t know

and | February 5, 2015

EGM_pngWhether you are a research funder, decision maker or researcher, keeping up with the ever expanding evidence base is not easy. Over 2600 impact evaluations and 300 systematic reviews assessing the effects of international development interventions have been completed or are ongoing to help answer that question and understand how, why and at what cost.  Despite this increase in quality evidence, more evidence is needed, which is why funders and researchers continue to fund and produce new research.

What reliable tools do we have to help us know what we know and don’t know? How can decision makers get a quick overview of the existing research evidence when it is scattered around different databases, journals, websites and the grey literature? Without having an effective and quick overview, how can commissioners of research ensure that limited resources are spent efficiently for prioritising the production of research that addresses important evidence gaps?

The International Initiative for Impact Evaluation (3ie) is addressing these key issues by introducing today its new, innovative and interactive, web-based platform for 3ie evidence gap maps (EGMs). Our EGMs consolidate what we know about what works in particular development sectors or thematic areas. They provide a graphical display of evidence from systematic reviews and impact evaluations in a given sector or thematic area.

In an easy-to-use way, the maps highlight areas with strong, weak or non-existent evidence on the effects of development programmes targeted for a given EGM exercise. Users can quickly explore an EGM and also go through the links to easy-to-read summaries of all studies. Through this interactive platform, we present research in a format that is useful and accessible for a range of audiences – policymakers, practitioners and researchers.

Funding research that matters

Why do we need EGMs?

EGMs can inform strategic research agendas and ensure that money is spent on studies that really matter. EGMs highlight gaps in the existing evidence base on the effects of development programmes. Identifying these gaps is of particular relevance for funders of impact evaluations who want to target their funding towards important areas where there is no research evidence. By also highlighting areas where we have a lot of evidence, EGMs can help reduce duplication of efforts.

For instance, our EGM on water, sanitation and hygiene interventions finds that few systematic reviews assess effects on outcomes other than diarrhoea, including time use and safety (particularly for women and girls) and economic outcomes. The map also clearly highlights that there is limited prospective impact evaluation evidence from Sub-Saharan Africa, in particular studies that assess sanitation and hygiene programmes at scale.

The World Bank’s Independent Evaluation Group and 3ie are now building on the work done on the EGM by producing briefs based on the identified evidence gaps. These briefs will inform the work of the World Bank’s newly formed Water Global Practice in making decisions on where evidence is most needed for improving lives. The EGM on water, sanitation and hygiene interventions is also being used to inform 3ie’s Sanitation and Hygiene grant programme.

In areas such as climate change adaptation or humanitarian interventions for instance, intervention typologies are not well defined and questions are broad. In such cases, EGMs are a useful first step for taking stock and building the evidence base.

Identifying trends and holes in research

EGMs quickly show you the broad trends in a particular area of research and throws up shortcomings. The 3ie EGM on productive safety nets maps the evidence on the effects of these interventions on poverty. We see from the EGM that the interventions focus on poverty reduction as an outcome, while also seeing that few existing studies actually measure poverty. Those that do often fail to define this appropriately. By highlighting such trends in evidence production, EGMs identify areas where future studies can add most value.

Primary studies are often conducted without sufficient attention to existing research, which means their results cannot be generalised beyond the study context.

This inattention presents a barrier to evidence synthesis and our ability to reach generalisable conclusions. Because EGMs include overviews of included interventions and outcomes, they can make it easier for researchers to review existing research when designing their studies and selecting outcomes. More robust studies with standardised outcome measures will improve the potential for future evidence synthesis.

Supporting evidence-informed policymaking

Policy processes often move quickly and decision makers do not always have time to wait for new impact evaluations and systematic reviews to be completed. In the meantime, EGMs can be conducted relatively quickly and therefore ensure that the best existing evidence is available when policymakers need it.

EGMs can reduce wasted opportunities to improve outcomes by making existing evidence available in an accessible and unbiased way. Since EGMs also highlight the quality of evidence, policymakers can make an informed judgement about what is credible and rigorous research.

An example of this is 3ie’s EGM of systematic reviews of education programmes. It covers a huge landscape of interventions in the primary and secondary education sector and provides users with easy access to a collection of 21 systematic reviews that assess the effects of different education interventions, including school feeding, cash transfers, teacher incentives and deworming.

A new brick in the evidence architectureUNAMID_7789103268

Are EGMs an alternative to new primary studies or systematic reviews? The answer is no.  If decision makers want to know the effects of a relatively well defined intervention or a limited set of interventions, a formal evidence synthesis based on a systematic review is the most appropriate tool.

But if there are no impact evaluations in a development area, there can be no policy findings from systematic reviews. And if there are no impact evaluations and systematic reviews, then the EGM will also be empty.

Our vision is to develop collections of evidence based on the EGM approach across a broad range of sectors and sub-sectors of relevance to low- and middle-income countries. 3ie is currently working on a range of EGMs, including on climate change adaptation, peace and state building and immunisation.

We hope you will join us in developing the evidence architecture by engaging with us on EGMs.

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