Despite emerging interest in mixing experimental and qualitative methods, a gap exists in inte- grating qualitative vignettes and experimental design. We present a novel mixed methods design, the qualitative vignette experiment, defined as the use of vignettes designed to introduce experi- mentally controlled variation in information within qualitative semistructured interviews. We argue that this design can provide context-rich data on causal mechanisms. This article contri- butes to the debate on integration in mixed methods research and is useful for scholars studying human practice and the link between macro-structural conditions and micro-interpretive pro- cesses. The design builds on an integrated ontology of critical realism and a complementary epis- temological foundation of postpositivism and interpretivism. This means that researchers have to adhere to multiple validity criteria.