It permits necessary revisions before the full effort goes forward. Its basic purpose is to maximize the chance for program success before the communication activity starts. The case studies reviewed by the subcommittee reveal that formative research and evaluation methods were used extensively by PHS agencies. This type of evaluation can also include examination of administrative and organizational aspects of the program. Outcome evaluation is used to obtain descriptive data on a project and to document short-term results.
Impact evaluation is the most comprehensive of the four evaluation types.
It is desirable because it focuses on the long-range results of the program, including changes or improvement in health status. Impact evaluations are rarely possible because they are usually costly, involve extended commitment, and may depend upon strategies besides communication. Information obtained from an impact study may include changes in morbidity and mortality changes in absenteeism from work long-term maintenance of desired behavior rates of recidivism. Appendix 2 provides an overview of evaluation strategies for assessing the efficiency and effectiveness of interventions. These strategies may include focus groups, observation studies, survey and baseline data, pretesting, and tracking.