Abstract.—The effect of supportive and nonsupportive analogues of supervision on introvert and extravert counselors' rating of own counseling performance was studied. Subjects in the treatment groups received either supportive or nonsupportive supervision following subjects' participation in a counseling interview. Differences between counselor ratings on the Counseling Relationship Maturity Scale immediately following the counseling interview and after treatment were analyzed. A control group received no supervision. The results indicate that nonsupportive as well as supportive supervision influence counselors' evaluation of the counseling interview, and that introverts were more influenced by nonsupportive supervision than extravert