Using vignettes to tap into moral reasoning in public health policy: practical advice and design principles from a study on food advertising to children.

In this article, we describe a process for designing and applying vignettes in public health policy research and practice. We developed this methodology for a study on moral reasoning underpinning policy debate on food advertising to children. Using vignettes prompted policy actors who were relatively entrenched in particular ways of speaking professionally about a controversial and ethically challenging issue to converse in a more authentic and reflective way. Vignettes hold benefits and complexities. They can focus attention on moral conflicts, draw out different types of evidence to support moral reasoning, and enable simultaneous consideration of real and ideal worlds. We suggest a process and recommendations on design features for crafting vignettes for public health policy.