Abstract: | The purpose of this study was to examine the effect that large, within-examinee item difficulty variability had on estimates of the proportion of consistent classification of examinees into mastery categories over two test administrations. The classification consistency estimate was based on a single test administration from an estimation procedure suggested by Subkoviak (1976). Analyses of simulated data revealed that the use of a single estimate for an examinee's probability of a correct response, even when that probability varied greatly within a test for an examinee, did not affect the estimation of the proportion of consistent classifications. |