Assessing normal and abnormal personality functioning: strengths and weaknesses of self-report, observer, and performance-based methods.

Assessing personality characteristics; distinguishing the boundaries between normal and abnormal functioning; identifying impairment in the domains of work, interpersonal relationships, and emotional state due to maladaptive personality traits; and translating these findings into effective, appropriate treatment interventions is a complicated endeavor. Valid, reliable conclusions about an individual's personality functioning and adjustment cannot be reached unless one has accurate information about that person's patterns of behavior, cognitions, emotions, and interpersonal relationships. I discuss strengths and weaknesses of assessment approaches utilizing explicit assessment methods, such as self-report measures and clinical interviews; information obtained from knowledgeable observers; and performance-based, implicit assessment methods such as the Rorschach Comprehensive System (Exner, 2003). In contrast to explicit methods of assessment, implicit methods can provide salient information about a personality construct whether or not individuals have accurately conceptualized that construct, have weighed how the construct describes them, are self-aware, and are willing to openly provide information relevant to that construct. I propose that the accuracy of conclusions about an individual's personality style, problems in adjustment, and treatment needs may be improved if conclusion are based on a multimethod assessment approach that incorporates information gathered using explicit assessment methods, information provided by significant others, and data from performance-based or implicit measures of personality.