Katherine Smith, Niklas Andreas Andersen and Valérie Pattyn
This blog post is based on the Evidence & Policy Special Themed Section ‘Learning Through Comparison’, Published in Evidence & Policy Vol 21 No 2, May 2025.
One of the central aspects of any process of learning and knowledge generation is the act of comparison. By comparing how our own ideas, norms and actions align or differ with those of others, we can see ourselves in a new light and thus better understand the particularities of our own situation as well as potentially re-evaluate taken-for-granted assumptions. This is true of every-day examples of individual learning as well as learning within and across research-communities. However, learning through comparison is also an inherently difficult endeavour as it often entails acquiring in-depth knowledge of research areas or settings that are (at least initially) completely foreign to us. This is perhaps one of the reasons why many fields of research often struggle to produce truly comparative research.
This is indeed the case with the now extensive research exploring, and trying to strengthen, the use of evidence in policy and practice. Single case studies and analyses of specific policy domains, countries or jurisdictions dominate this literature, limiting our ability to understand and compare how evidence, and evidence-for-policy mechanisms, function across time, and distinct institutional, national, and disciplinary contexts. The consequence is, we suggest, that we’re likely to be missing opportunities for cumulative knowledge building (in research) and lesson drawing (in practice).
Comparison allows researchers to identify patterns and contradictions that might otherwise remain hidden within isolated within-case studies. It also offers opportunities to enhance our conceptual understanding, through learning about theories developed in other areas and by understanding how similar concepts are differently described across disciplines and topics. Comparison therefore contributes to both deeper conceptual clarity as well as practical problem-solving, which can help in designing more effective evidence-for-policy interventions.
These discussions where central to a fruitful Centre for Science, Knowledge and Policy at Edinburgh (SKAPE) workshop in June 2022, which provided the impetus for us to guest-edit this special themed section on learning through comparison in Evidence & Policy.
Three Key Insights from Comparative Research on Evidence and Policy
Reading across the four papers included in the special themed section of Evidence & Policy, each of which applies a comparative lens to evidence-informed policymaking, we identify three overarching themes:
1. Disciplinary Dominance within some Evidence Cultures
A recurring issue in policymaking is determining what ‘counts’ as valid evidence. All four special issue papers suggest that the answer to this question varies across different settings, but there is a common tendency for specific scientific disciplines to become dominant within each setting. For example, research on organisations designed to support parliamentary access to evidence in France, Germany, and the UK shows that, despite the COVID-19 pandemic highlighting the need for social science insights, STEM (science, technology, engineering, and mathematics) disciplines dominated the evidence cultures of all three institutions. Instead, a paper focusing on policy evaluations in Denmark and the Netherlands demonstrates how economic preferences, driven by finance ministries, prioritise an evaluative focus on cost-benefits, rather than broader policy learning.
While these disciplines all have a great deal to offer policymakers, it is important to recognise where and how disciplinary norms function to filter out other types of (potentially useful) evidence. A more inclusive and interdisciplinary approach to evidence, integrating diverse knowledge sources, can thus enrich policy discussions and lead to more holistic decision-making.
2. The Role of Politics and Democratic Legitimacy
Another consistency across the four special issue papers is the way in which they underline the importance of understanding the political and institutional realities in which efforts to support the use of evidence in policy occur. Policymakers must navigate trade-offs between scientific expertise and public values, ensuring that evidence is used to support – not override – democratic processes.
Studies in this themed issue highlight how policies can fail if key stakeholders – such as frontline workers and affected communities – do not perceive them as legitimate. In Denmark, for instance, policies in education and employment sectors that did not adequately engage key professionals in their formulation faced significant resistance during implementation.
3. The Need for Realism in Efforts to Enhance Evidence Use in Policy Settings
The complexity of policymaking necessitates a pragmatic approach to integrating evidence, which is also clearly demonstrated in the themed issue. Comparative research underscores that policymakers often engage in ‘epistemological bricolage’, piecing together different sources of information based on what is available and politically feasible. Even the best evidence will only be useful if it is timely, accessible, and aligned with institutional realities.
This is most evident in the special themed section’s Practice paper, which brings together reflections from three researchers who each transitioned into policymaking roles. Their accounts reveal that even rigorous evidence may not always fit neatly into the fast-paced world of political decision-making. Politicians tend to require synthesised, actionable insights that align with existing policy windows and political priorities – this is often quite different from the type of evidence that academics tend to produce.
Moving Forward: The Future of Comparative Evidence Research
The insights from this special themed section highlight the importance of interdisciplinary collaboration, cross-national learning, and learning with and from practitioners. Future efforts should focus on breaking disciplinary silos, fostering knowledge exchange across different policy sectors, and ensuring that evidence-use strategies are informed by the realities of specific political and institutional contexts.
Funding initiatives that encourage collaborations between researchers and policymakers – such as fellowships that allow researchers to spend time in government and vice versa – can help foster some of the learning required to support evidence use in policy. Although, these papers suggest that it may be as important to understand variation within (as well as between) policy settings.
Conclusion
The different papers in this special themed section show how the push for evidence-based policymaking must be accompanied by a commitment to understanding how evidence is used across different settings. Through comparative cross-case research, we can uncover valuable lessons about the interplay between evidence, politics, and policy design, and identify how the complexities and diversity of policymaking impact the production and use of knowledge sources. Comparative studies can also help pointing to areas of cross-context inspiration, that can ultimately further the effectiveness, responsiveness and democratic legitimacy of the evidence used to inform policymaking.
Image credit: Photo by reyna on Unsplash
Kat Smith is a Professor of Public Health Policy at the University of Strathclyde, where she co-leads the Centre for Health Policy and the Scottish Health Equity Research Unit
Niklas Andreas Andersen (PhD) is associate professor at the Department of Politics and Society at Aalborg University. His research focuses on the institutionalisation of evaluations and Evidence-based Knowledge in processes of policymaking.
Valérie Pattyn is associate professor of public policy and policy analysis at the Institute of Public Administration at Leiden University, and visiting professor at KU Leuven Public Governance Institute. She specialises in evidence-informed policy making, policy design and policy evaluation.
Read the Editorial to the Learning Through Comparison Special Themed Section:
Smith, K.E. Andersen, N.A. & Pattyn, V. (2025). Learning through comparison when studying evidence and policy. Evidence & Policy, 10.1332/17442648Y2025D000000051.
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The organisation of evaluations: the influence of the ministry of finance on evaluation systems
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