Process evaluations of the 5-a-Day projects

Process evaluation is an important, but infrequently conducted, component o f evaluating the impact of health promotion interventions. The process eval uation results from the nine 5-a-Day projects were overviewed. Process eval uation helped explain some of the weaker aspects of program performance, pr ocess indicators occasionally declined over time and varied by demographic characteristics, and some process measures were related to mediating variab les and program outcomes. Future development of process evaluation must inc lude further development of concepts, more consistent and thorough conduct of process evaluation, appropriate methodological work, and assessment of t he relations among the process evaluation components and the program mediat ors and outcomes. Further development in this area promises refinement in u nderstanding how and why interventions achieve their effects, how best to c onduct intervention programs to maximize effects, and enhancement of the in ternal and external validity of the studies.