Intuitive Data Processing as a Potential Source of Bias in Naturalistic Evaluations

in the 17th century, for example, rebelled against the influence of Aristotelian thinking and the methods of acquiring knowledge (especially about the physical universe) current in his own day. In particular, he warned against a number of sources of distortion which he called Idols. Those associated with sensory perception and intuitive methods of analysis he called the "Idols of the Tribe," since he believed them to be "inherent in human nature, and the very tribe or race of man" (Bacon 41). Recent research in human perception and cognition has given substance and specificity to many of Bacon's concerns. In addition, there has been growing interest in the implications of this type of research in various social settings, in particular, to courtroom testimony (Yarmey, 1979) and to decision making in business (Wright, 1980). Because bias threatens an evaluation, it is not surprising that there is considerable literature on the topic. It is possible to group various forms of bias under three broad headings. First, there are ethical compromises, actions for which the evaluator is personally culpable. Second are what may be called value inertias, unwanted distorting influences which reflect the evaluator's background experience. The first part of this paper is a brief survey of these two categories, mainly to indicate the scope of each and so distinguish them from the third category, cognitive limitations in dealing with data. The major purpose of the paper is to elaborate the third category. This takes the form of a survey of faulty intuitions which have been identified in empirical research. Only those aspects which appear to have direct relevance to evaluation (in particular, naturalistic evaluation) are included. This is not to suggest that current naturalistic approaches to research and evaluation are undisciplined and merely impressionistic. They are not, of course. But such a catalog of commonly-found intuitive biases is justified even if it is not accompanied by concrete proposals as to how each may be eliminated or reduced. To be sure, the presentation may appear to be somewhat negative (after all, it is a list of defects) but if it helps sensitize naturalistic inquirers to potential problem areas, its contribution will be positive.