Interactivity has been shown to be a critical element of effective drug abuse prevention programs. This study examined the contents of Project Towards No Drug Abuse, a program that has revealed strong effects only when delivered in a highly interactive version. Types of teacher and student interactive messages were identified. It is speculated that explicit action on the part of the teacher to have students make statements and ask questions of one another may be the essence of effective drug education program delivery. Suggestions for future research on interactivity were made. (Contains 2 tables.)