Formative evaluation refers to appraisals of quality focused on instructional programs that are still capable of being modified. Formative evaluation, in a more general sense, is used to assess effect, worth, or progress while the treatment is in progress. The process is proactive in nature. When evaluation results indicate a need for program modification, the evaluator makes recommendations for change and provides suggestions for program improvement.

Summative evaluation is the appraisal of quality at the end of program or project activities and is retroactive in nature. Decisions pertaining to the overall worth or effectiveness are made based on the results of summative evaluation, and it is these decisions that influence current and future practices. Summative evaluation results also serve as the basis for goals or objectives for future program planning and improvement.