All seven strategies were representative of current school-based prevention programs in affective education, alternative programs, or drug education and could be implemented at moderate cost. Four strategies -- inservice teacher training courses that focused on classroom and individual factors influencing attitudes toward school and self-esteem -- were called magic circle, effective classroom management-elementary, effective classroom management-junior, and jigsaw. Two alternative strategies, offered as elective academic courses to junior high students, were cross-age tutoring and operating a school store. The final strategy was a drug education course that taught social competencies and drug information to seventh graders. One or more separate evaluations of each strategy were conducted during the course of the project. In addition, two or three strategies were provided to the same group of students over a 2-year or 3-year period. In these cohort studies, the cumulative effects of the strategies were measured. All the studies used experimental or quasi-experimental designs. With the exception of drug education, the strategies failed to produce the hypothesized outcomes. The four teacher-led inservice strategies and the two alternative strategies had no systematic and predictable effect on students relevant to perceptions of classroom climate; attitudes toward self, peers, or school; attendance; academic achievement; perceptions of peer group norms; or drug-related attitudes, intentions, or behaviors. Three separate replications and evaluations of the drug education course showed it to have no pattern of effects on seventh or eighth grade boys, but provided some evidence of positive short-term effects only on seventh grade girls. The lack of overall effects does not seem attributable to the quality of implementation or evaluation research. The strategies may have been ineffective because they were based on an inadequate theory of substance abuse prevention. The theory underlying the strategies holds that greater attention to students' affective needs will enhance constructive social attitudes, norms, and competencies, which in turn will decrease the acceptance of and involvement in drug use. The evaluation studies do not provide any empirical support for this theory. One figure, data tables, and 31 references are supplied. (Author summary modified)