Reasons for Minnesota Multiphasic Personality Inventory (MMPI) and Rorschach disagreement at the nomothetic level are explored. Building on an understanding of measurement distinctions from other sciences, it is proposed that the Rorschach and MMPI procedures are differentially sensitive to unique manifestations of personality. By necessity, each method is then also recognized as having a limited scope of effectiveness, such that neither can provide a complete picture of personality in its full complexity. Drawing on the more extensive self-report literature, the idiosyncracies and limited scope of the self-report method are documented. Finally, an ideographically rooted, cross-method, configural model is proposed for validation research in personality assessment. Several examples consistent with this approach are drawn from the assessment literature and discussed.
