In the past, many school based dental health education programs have appeared to fail to bring about changes in children's behavior or measureable improvements in oral health. The reasons why this has been so are not always clear, but part of the explanation may be that inadequate attention has been paid to the research preceding the development of the dental health education materials used in the programs. This paper describes a rational planning cycle for evaluation research, which includes problem definition research, planning research, audience pre-testing and post-production audience testing for acceptability. Further stages involve post-dissemination evaluation, which include measures of effectiveness and implementation, but this paper argues that the four phases described above constitute a logical means of providing target groups with appropriate, acceptable and efficacious material.