Seven routes to experimentation in policymaking: a guide to applied behavioural science methods

OECD Resource: “…offers guidelines and a visual roadmap to help policymakers choose the most fit-for-purpose evidence collection method for their specific policy challenge.

Source: Elaboration of the authors: Varazzani, C., Emmerling. T., Brusoni, S., Fontanesi, L., and Tuomaila, H., (2023), “Seven routes to experimentation: A guide to applied behavioural science methods,” OECD Working Papers on Public Governance, OECD Publishing, Paris. Note: The authors elaborated the map based on a previous map ideated, researched, and designed by Laura Castro Soto, Judith Wagner, and Torben Emmerling (

The seven applied behavioural science methods:

  • Randomised Controlled Trials (RCTs) are experiments that can demonstrate a causal relationship between an intervention and an outcome, by randomly assigning individuals to an intervention group and a control group.
  • A/B testing tests two or more manipulations (such as variants of a webpage) to assess which performs better in terms of a specific goal or metric.
  • Difference-in-Difference is an experimental method that estimates the causal effect of an intervention by comparing changes in outcomes between an intervention group and a control group before and after the intervention.
  • Before-After studies assess the impact of an intervention or event by comparing outcomes or measurements before and after its occurrence, without a control group.
  • Longitudinal studies collect data from the same individuals or groups over an extended period to assess trends over time.
  • Correlational studies help to investigate the relationship between two or more variables to determine if they vary together (without implying causation).
  • Qualitative studies explore the underlying meanings and nuances of a phenomenon through interviews, focus group sessions, or other exploratory methods based on conversations and observations…(More)”.