Assessing Diagnostic Expertise of Counselors Using the Cochran–Weiss–Shanteau (CWS) Index


concerning this article should be addressed to Cilia L. M. Witteman, Behavioural Science Institute, Radboud University Nijmegen, PO Box 9104, 6500 HE Nijmegen, The Netherlands (e-mail:


Counseling studies have shown that increasing experience is not always associated with better judgments. However, in such studies performance is assessed against external criteria, which may lack validity. The authors applied the Cochran–Weiss–Shanteau (CWS) index, which assesses the ability to consistently discriminate. Results showed that novice counselors performed almost on the same level as very experienced counselors. The authors thus replicated earlier findings with a novel approach: applying an internal coherence criterion.