This collection of studies covers a broad range of school-based prevention activities. The distribution of effects for delinquency, AOD use, truancy/drop out, and other problem behaviors has been discussed else- where. The focus of this paper is the relationship between the AOD use outcomes and characteristics of the population (i.e., high risk vs. gen- eral school population and age or development stage of the program participants), and selected character- istics of the intervention program (i.e., program dura- tion and person delivering the service). Each of these relationships is explored below. An analysis of the ro- bustness of the findings to methodological variability across studies is also presented.