Counselors should be able to increase their effectiveness by appropriate use of social influence strategies; learning to use power bases is a critical need of counselor trainees. One way they can learn to use power bases is by modeling their supervisors in counseling practica. In this study, the effects of faculty supervisors' attitudes on counseling trainees' attitudes toward power bases were examined. Supervisors' and trainees' attitudes were measured using a questionnaire developed by Robyak (1981) for assessing referent, legitimate, and expert power base preferences. During a one-semester counseling practicum, pre/post measures of preference strength were obtained from 50 trainees in 8 supervisory groups. Analysis of variance procedures yielded no significant differences between repeated measures or between groups. Observed trends consistent with desirable use of power bases indicated that trainees were not unduly influenced by their supervisors' preferences. Implications of these results for counselor training programs are discussed, and references are included. (Author/TE)