to practice health-enhancing behaviors and reduce health risks." Although behavior change as an outcome for health education can be found in textbooks written at midcentury as one of the three desirable outcomes in health education (changes in knowledge, attitudes, and behavior), not until 1979 when the Surgeon General's report Healthy People (U.S. Department of Health and Human Services, 1979) revealed that 50 percent of premature death and illness was caused by life-style choices, did a focus on behavior became prepotent. Health educators and public health officials began to shift their emphasis to behavioral outcomes, once it was established that knowledge alone does not change behavior.²

Desired practice in health education requires that effective curricula be selected and implemented by well-prepared teachers. There have been a number of studies demonstrating the effectiveness of health education curricula that target a single specific behavior (Glynn, 1989; Stone et al., 1989), as well as studies of programs that use a comprehensive health education curriculum to prevent or reduce certain debilitating behaviors such as tobacco, alcohol, and drug use; imprudent dietary behaviors; physical inactivity; and inappropriate sexual behaviors (Botvin and Eng, 1982; Connell et al., 1985; Ross et al., 1989; Williams et al., 1983). Table 3-6 identifies some illustrative studies of the outcomes of various health education curricula. Two large-scale evaluations have found that (1) students' knowledge of health behaviors increases after instruction; (2) students' behaviors, especially those related to substance abuse, become more health enhancing; (3) "booster sessions" are required up to two or three years after the initial program to maintain the desired effect; (4) greater changes in behavior occur after 50 hours of instruction; and (5) teachers who received training implement the curriculum with more fidelity and achieve more positive effects than teachers who do not receive training (Connell et al., 1985; Ross et al., 1991).

Two systems are currently in place for curriculum developers to disseminate exemplary evaluated curricula. One method is to apply to the U.S. Department of Education National Diffusion Network. If the developer can demonstrate strong evaluation data that establish the impact of the curriculum, it may be "accepted" into the National Diffusion Network and dissemination funding can be obtained. Another means is to submit detailed evaluation results to the Division of Adolescent and School