Despite its intuitive appeal and popularity, Thorndike's constant ratio (CR) model for unbiased selection is inherently inconsistent in "n"-free selection. Satisfaction of the condition for unbiased selection, when formulated in terms of success/acceptance probabilities, usually precludes satisfaction by the converse probabilities of…

Within the beta-binomial Bayesian framework, procedures are described for the evaluation of the kappa index of reliability on the basis of one administration of a domain-referenced test. Major factors affecting this index include cutoff score, test score variability and test length. Empirical data which substantiate some theoretical trends deduced…

A number of different reliability coefficients have recently been proposed for tests used to differentiate between groups such as masters and nonmasters. One promising index is the proportion of students in a class that are consistently assigned to the same mastery group across two testings. The present paper proposes a single test administration…

Decision theory is a useful method for assessing the effectiveness of the components of a course placement system. The effectiveness of placement tests or other variables in identifying underprepared students is described by the conditional probability of success in a standard course. Estimating the conditional probability of success is discussed.…

The effect of large, within-examinee item difficulty variability on estimates of the proportion of consistent classification of examinees into mastery categories was studied over 2 test administrations for 100 simulated examinees. The proportion of consistent classifications was adequately estimated using the technique proposed by M. Subkoviak…