Chapter 5 discusses how competency in assessment and case formulation are fundamental components of board certification for every psychological specialty, and how assessment, psychological testing, and case conceptualization are fundamental aspects of the professional practice of counseling psychology and complement treatment and intervention. Competency in each of these areas is judged in the examination for board certification in counseling psychology. In each case, culturally concordant and ethically appropriate practice is expected. It also covers a brief history of assessment and cultural context, culturally appropriate assessment, clinical vs. actuarial assessment, and diagnostic classifications.