These studies in test adequacy focus on two problems: procedures for estimating reliability, and techniques for identifying ineffective distractors. Fourteen papers are presented on recent advances in measuring achievement (a response to Molenaar); "an extension of the Dirichlet-multinomial model that allows true score and guessing to be…

A closed sequential procedure for estimating true score is proposed for use with answer-until-correct tests. The accuracy of determining true score is the same as in conventional sequential solutions, but the possibility of using an unnecessarily large number of items is eliminated. (Author/CM)

Mastery tests are analyzed in terms of the number of skills to be mastered and the number of items per skill, in order that correct decisions of mastery or nonmastery will be made to a desired degree of probability. It is assumed that a random sample of skills will be selected for measurement, that each skill will be measured by the same number of…