In the last fifty years, the use of stories in education has included vignettes as an effective stimulus for discussion of real-life contexts and problems. However, vignettes have rarely been used as an assessment tool and there is no reported consensus on their definition and design. This article documents the use of vignettes as an effective method of assessing pedagogical understanding in our teacher development courses from 1995-2003, suggesting that vignettes are significantly correlated with more traditional forms of assessment, are highly predictive of course-ending project performances, and represent an episode of learning in their own right. Finally, we propose a more concise definition and a more rigorous course of study for vignette development and implementation. (Contains 1 footnote.)