The relative contribution of four kinds of data to accuracy in personality assessment.

Does the information available to the clini-cal psychologist through his tests and other resources, as in the psychodiagnostic process, provide him with a significant amount of un-derstanding of the patients about whom he is asked to make judgments, descriptive and diagnostic statements, and for whom he is asked to make decisions? This question im-plies others: (a) if significant insights into patients are possible via the information avail-able to the psychologist, which kinds of data contribute most to an adequate level of un-derstanding, (b) what is the relationship be-tween the amount of data available to the clinician and the degree of insight he achieves, and (c) is it possible to identify most effi-cient batteries of tests and/or other data. More precisely, we see that it is not only the data themselves in which we are interested but the data as they are used by the psy-chologist. As Kelly (1954) has noted, the in-troduction of the human element into the assessment process means that the techniques of assessment (tests, data) have validity which is not independent of the assessor. The problem is, then, one of evaluation of inter-action between data and user. 1 This paper is based upon the doctoral disserta-