“What if someone had already figured out the answers to the world’s most pressing policy problems, but those solutions were buried deep in a PDF, somewhere nobody will ever read them?” asked a Washington Post blog last year.
It was on to something. Many of the tens of thousands of documents that are produced every year to assess the impacts of sustainability policies and programmes are never read. In 2014, the World Bank found that almost one-third of its archived policy reports — documenting the impacts of its numerous projects, from dam construction to microcrediting — has never been downloaded.
It doesn’t have to be this way. Experts in evidence synthesis, a field that involves the use of various tools and methods to locate and combine many sources of data, are starting to produce evidence maps for wayfaring researchers and policymakers. These pull together and categorize systematic reviews, impact evaluations and other primary-research studies in a particular area (such as agriculture or education), and visually distil the scope and effects of interventions that have been implemented.
Evidence maps can show at a glance which areas or relationships have been studied most — whether it be the impact of ecotourism on local economies or of education on reducing harmful fishing practices. They can also highlight key gaps in the evidence base, and so guide the prioritization of research.