What is a critical difference between formative and summative evaluation?

The critical difference highlighted by the correct choice is that formative evaluation is primarily concerned with ongoing improvement throughout the course of a program, while summative evaluation is focused on assessing the final outcomes after the program has been implemented. Formative evaluation typically takes place during the development or implementation phases. Its purpose is to provide continuous feedback that can help shape and enhance the program, ensuring that it meets its goals effectively.

On the other hand, summative evaluation is conducted after the program's completion to determine its effectiveness and impact, assessing whether the intended outcomes have been achieved. This type of evaluation often involves evaluating the overall success and making decisions about program continuation or modification based on the results.

Understanding this distinction is essential for program evaluators, as it helps them choose the appropriate evaluation approach for different stages of a program's lifecycle and understand the implications of the findings for program improvement and decision-making processes.