On the first day of a graduate psychology class in diagnostic interviewing, students are asked to describe what it takes to be a great detective. Keen observation, curiosity, strategic questions, perseverance, and deductive reasoning are some of the many qualities attributed to Sherlock Holmes, Miss Marple, Colombo, and Inspector Morse. The instructor then asks the class to consider how these same qualities might be applied in clinical practice-especially in relation to assessment and case conceptualization. Many parallels are drawn, as being a good clinician often calls for similar skills and experiences as a detective. In fact, some cognitive behavioral therapists even describe therapy to their clients as a collaborative investigation of the problem and search for possible solutions as in the case of detectives or scientists (e.g., Beck, 1995).
Regardless of clinicians' orientation, the ability to carry out a thorough investigation of a client's presenting problem is key to psychotherapy (e.g., Morrison, 1995). Clinicians use assessment to understand what brings the client to therapy, what types of treatment might be appropriate, and monitor whether interventions are helpful. In particular, there is a growing emphasis on the benefits of one aspect of assessment in clinical practice-ongoing evaluation of client progress in therapy or formal treatment outcome assessments (e.g., Lambert et al., 2001; Truax, 2002). Yet there are many challenges in clinical practice