At first glance, this competency may seem somewhat tangential to the overall topic of essential competencies. It might seem that this competency would be better included in a book or training manual on supervisory competencies. Actually, because supervision is a primary means of developing and evaluating psychotherapy competencies, many consider the effective use of supervision by trainees to be an essential intervention competency (Haynes, Corey, & Moulton, 2003). For this reason, this competency is addressed in this book.