This paper describes a computer program based on the premise that successful counseling can be viewed as an interpersonal influence process composed of three basic features: sequentiality, flexibility, and constraint. An introduction to the INTERACT program explains how the program analyzes counselor/client and client/counselor transitions or response contingencies. Data entry is explained and six program outputs are discussed: (1) counselor and client response frequency counts; (2) matrix of counselor-client contingency frequencies; (3) matrix of counselor-client transition probabilities; (4) counselor-counselor and client-client transition matrix; (5) information/association measures; and (6) relative influence. The benefits of the program to counseling students are discussed and technical notes are provided which describe needed hardware and availability. A series of figures presenting sample printouts for each of the program areas concludes the paper. (JAC)