How to create personas to improve designs for behaviour change strategies in the public domain? Three recent cases illustrate lessons learnt and challenges encountered during persona development in the public domain. Personas were helpful to gain insight into diversity within a target group, to create empathy for its members, and to have a shared understanding when communicating about them. The main challenges encountered were 1) capturing complex behaviour with personas, as the behaviours involved were variable over time, the (legislative) environment in motion, and the target groups diverse; 2) finding the right balance between intuitive
vs. evidence-based decision-making, a process we coined “taking a responsible leap of faith”; and 3) transferring personas to third parties, as free sharing of insights and tools is common in the public domain. Validation plays an important role in personas’ transferability. We call for all involved researchers to share experiences with using the persona methodology in the public domain, in order to tackle the challenges, and to create a more standardised way of developing personas.