T he power of psychological assessment can be fully realized only when we move beyond the identification of linear score-behavior relationships and integrate multisource data in a manner that describes, explains, and predicts complex human behaviors (Handler & Meyer, 1998). Unfortunately, achieving this degree of proficiency in psychological assessment is challenging and requires more than experience and technical skill. An explicit knowledge of how personality works is required to become a truly expert assessment psychologist. In particular, such an understanding of personality is essential for organizing and systematically integrating assessment findings (Blais & Smith, 2008; Handler & Meyer, 1998). In this chapter we present a personality focused approach to psychological assessment that uses a model of personality organization (PO) to enhance the data interpretation and integration.