READING-COMPREHENSION TEST ITEM DIFFICULTY AS A FUNCTION OF COGNITIVEPROCESSING VARIABLES

This study reports the results of a componential analysis of items com prising Sections A and C of Form Z of the reading comprehension portio ns of the California Achievement Tests (CAT) Tiegs & Clark, 1963). A s et of problem components or attributes characterizing the test items o f manifest content, psychologically salient features, and processing d emands was developed, including methods for their quantification. The contributions of these components to task difficulty were then evaluat ed using linear regression methodology. Item difficulty indices were t ransformations of the familiar proportion-correct item score, obtained from data gathered during the spring of 1989 from 158 deaf examinees. Variation in the item difficulty values was substantially accounted f or in terms of a small number of predictor variables (R2 greater-than- or-equal-to .90). Implications of the results for construct validity a nd interpretation of test scores are discussed.