This study examined the types of information counselor supervisors do not disclose to their trainees. Results from a national sample of 90 supervisors indicated that their nondisclosures fell into 12 categories, and that there were 9 reasons associated with these 12 types of nondisclosures.A primary role of counselor supervisors is to provide feedback to their trainees to enhance their learning and competence (Bernard & Goodyear, 1992;Blocher, 1983;Holloway, 1992). Because feedback could be limitless, yet time is limited, supervisors must choose to disclose only a subset of their reactions, thoughts, and feelings. Conversely, supervisors must choose to withhold or not disclose information to their trainees, presumably information that would detract from their learning. However, it is likely that, at times, supervisors do not share relevant growth-enhancing information with their trainees (e.g., salient information regarding the trainee's counseling skills or supervision behaviors), which could affect the efficacy of supervision. Although covert processes such as nondisclosures have been addressed generally in the counseling literature (e.g., Hill, Thompson, & Corbett, 19921, there has been little research on covert processes in supervision (Ladany, Hill, Corbett, & N u t t , 1996;Yourman & Farber, 1996). and no empirical studies that examine supervisor nondisclosures. Supervision theorists have to some extent addressed the role of covert processes in supervision. For example, Blocher (1983) noted that for supervision to be effective, communication patterns should be established through which both supervisor and trainee are able to express themselves with "minimal inhibitions and distortions" (p. 30). Bordin (1983) also indicated that to gain mutual trust and to build a stronger supervisory working alliance with the trainee, the supervisor should discuss her or his own experiences. Hence, if the supervisor is making very few disclosures in the supervision session, it is unlikely that an open and honest exchange is occurring.Alternatively, a reasonable argument could be made that not all supervisor nondisclosures should be disclosed. Some supervisor experiences, such as personal issues not relevant to supervision, even if thought about in supervision, would likely undermine the supervision process. Furthermore, supervisors who disclose too much information about themselves that has little to do with supervision, could weaken the supervisory relationship or negatively influence trainee growth. Therefore, supervisors must consider the effect that their nondisclosures could have on supervision effectiveness.We believed that the content of the thoughts, feelings, and reactions that supervisors do not disclose to their trainees would generally reflect aspects of the client-trainee-supervisor triad. Specifically, we reasoned that the content of the supervisor nondisclosures would generally pertain to the supervisor's personal issues and concerns (e.g., a personal family crisis), supervisor and trainee interactions (e.g...