Although consultation models have expanded, research demonstrating the effectiveness of consultation has lagged far behind, thus limiting the acceptance of consultation as an accountable method of intervention in schools. This study, which has implications for all "internals," presents a preventive consultation framework and demonstrates its effectiveness in working with school principals to change the climate of staff meetings.Undoubtedly, Sherlock Holmes is the best known of all modern consultants, and certainly he was the first person to apply the term &dquo;consulting&dquo; to his behavioral-science work. Holmes did his best to demystify the consultation process, to make it elementary to his biographer, Dr. Watson. With his advanced skills in nonverbal behavior, active listening, and experience clarification, Holmes developed the deductive process that he used successfully with a wide variety of clients. His well-documented interventions demonstrated clear results.Since Holmes's time the models of consultation have expanded few studies exist that document the processes and demonstrate the effectiveness of consultation.The purposes of this article are (a) to describe a model of consultation useful in school systems or for other organizations, (b) to present a conception of schools as a psychological context, and (c) to demonstrate a research design that assesses the effectiveness of consultation in an internal setting (an elementary school, in this case).