Systematic maps occupy a distinctive place in the evidence synthesis landscape. Unlike systematic reviews, which seek to answer a narrowly defined question by appraising and combining the results of individual studies, systematic maps are designed to describe the breadth of a research field. They catalogue what has been studied, where, how, and with what methods, providing a structured overview that can reveal clusters of activity and, just as importantly, blind spots. For a topic as sprawling as evidence use in policy—a field that draws on political science, public administration, sociology, psychology, and evaluation studies—such a cartographic exercise is not merely useful but arguably essential.

The updated map described in the article builds on earlier systematic mapping work in this domain, reflecting a field that has grown rapidly over the past two decades. The movement often labelled evidence-based policy has generated an enormous volume of empirical and conceptual scholarship, examining everything from the role of think tanks and knowledge brokers to the impact of research funding incentives and the cognitive biases of decision-makers. The task facing the authors of the map was to impose order on this abundance: to search systematically across academic databases, apply transparent inclusion criteria, screen thousands of records, and code the studies that survived screening according to a consistent framework.

That framework matters. A systematic map is only as good as its coding scheme, and the categories used to classify factors influencing evidence use inevitably shape the picture that emerges. Common clusters in this literature include the characteristics of the evidence itself—its perceived quality, relevance, timeliness, and accessibility; the characteristics of the policy context, including political will, institutional capacity, and the presence of formal requirements for evidence in decision-making; the characteristics of individual actors, such as policymakers’ trust in researchers and their training in interpreting quantitative findings; and the characteristics of the interactions between the two worlds, encompassing knowledge translation mechanisms, intermediaries, co-production arrangements, and personal networks.

One of the most robust findings across decades of research in this area is the persistence of what scholars have long called the gap between the production of evidence and its use. Early models assumed a linear process in which researchers generate knowledge and policymakers apply it, but the empirical literature has repeatedly shown that policy is driven by a far messier set of influences. Ideology, public opinion, lobbying, fiscal pressures, and electoral cycles all compete with research findings for attention and authority. As a result, contemporary scholarship tends to conceptualize evidence use not as a simple transfer but as a social process of exchange, negotiation, and sense-making, in which different forms of knowledge—including professional experience, stakeholder input, and political judgement—interact with scientific research.

The updated map’s contribution lies partly in its comprehensiveness and partly in its currency. Fields evolve, and a map that seemed current a few years ago can quickly become outdated as new studies multiply. By refreshing the search and incorporating recent literature, the authors were able to capture developments such as the growing interest in knowledge brokering organizations, the expansion of behavioural insights units within governments, and the intensified scrutiny of evidence use that accompanied policymaking during global crises. Each of these developments has generated new empirical work, and mapping it allows the field to see whether emerging themes are merely fashionable or whether they represent sustained areas of investigation.

Methodologically, the map also sheds light on how researchers have studied evidence use. The literature is dominated by qualitative approaches—case studies, interviews, and documentary analysis—alongside a substantial body of conceptual and theoretical writing. Quantitative measurement of evidence use remains comparatively rare, in part because use itself is notoriously difficult to define and observe. Does evidence use mean that a citation appears in a policy document, that a policymaker reports being influenced by research, that a programme design reflects a specific finding, or that outcomes improve after an evidence-informed intervention is adopted? Each definition leads to different methods and different conclusions, and the map makes these methodological patterns visible in a way that individual studies cannot.

The practical implications of such mapping are considerable. For funders, a systematic map indicates where investment in new research is most likely to yield genuine advances rather than duplicating existing work. For practitioners—knowledge brokers, science advisors, and research-impact officers—it provides an organized inventory of the factors that empirical studies have linked to successful evidence uptake, which can inform the design of translation activities and partnership programmes. For policymakers themselves, the map is a reminder that the barriers to evidence-informed decisions are rarely about the absence of research alone; they are frequently embedded in institutional incentives, time pressures, and the structure of the policy process.

The gaps revealed by the map are as instructive as its clusters. Coverage is uneven across policy domains, with education, health, and environmental policy attracting disproportionate attention while other sectors remain understudied. Much of the literature originates in high-income, English-speaking countries, raising questions about the transferability of findings to different political and administrative cultures. Longitudinal studies that trace evidence use over time are scarce, as are studies that follow specific pieces of research from publication to policy outcome. And the perspectives of certain actors—frontline implementers, citizens, and marginalized communities—are underrepresented relative to those of senior officials and academic researchers.

Ultimately, the updated systematic map serves as both a stocktaking exercise and an agenda-setting device. It consolidates what the field knows about the factors influencing evidence use in policy, makes that knowledge navigable, and highlights the questions that remain open. In an era when governments face contested information environments and heightened demands for accountability, understanding how research actually enters—and sometimes fails to enter—the machinery of government has never been more consequential. Maps of this kind do not resolve those questions, but they ensure that the next generation of researchers begins its work with a clear-eyed view of the terrain already travelled.

Subject of Research: Factors influencing the use of evidence in public policy, examined through an updated systematic map of the research literature

Article Title: What factors influence evidence use in policy? An updated systematic map

Article References: What factors influence evidence use in policy? An updated systematic map. (n.d.). https://doi.org/10.1038/s41599-026-08391-6

Image Credits: AI Generated

DOI: 10.1038/s41599-026-08391-6

Keywords: evidence use, policy, systematic map, evidence-based policy, knowledge translation, knowledge brokering, evidence synthesis, policy process, research uptake, science-policy interface, factors, influence