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

Does the information available to the clinical psychologist through his tests and other resources, as in the psychodiagnostic process, provide him with a significant amount of understanding 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 implies others: (a) if significant insights into patients are possible via the information available to the psychologist, which kinds of data contribute most to an adequate level of understanding, (b) what is the relationship between the amount of data available to the clinician and the degree of insight he achieves, and (c) is it possible to identify most efficient 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 psychologist. As Kelly (1954) has noted, the introduction 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 interaction between data and user.