RESUMO
Developmental evaluation is an emerging approach to program evaluation that emphasizes innovation and learning. It is particularly well suited to evaluating innovative programs in their earliest stages of development and adapting existing programs to complex or changing environments. Key features of the developmental evaluation approach include a tight integration between evaluators and program staff and the use of data for continuous program improvement. This article presents developmental evaluation as a complementary approach to the traditional formative-summative evaluation cycle, especially when used for preformative evaluation. To illustrate this emerging approach, the article features a case example from the Illinois Caucus for Adolescent Health's evaluation of its school board sexuality education policy change project. The article concludes by suggesting ways that developmental evaluation can be useful in health promotion practice.