The sampling errors of maximum likelihood estimates of item-response theory parameters are studied in the case where both people and item parameters are estimated simultaneously. A check on the validity of the standard error formulas is carried out. The effect of varying sample size, test length, and the shape of the ability distribution is…

In this study, simulated and actual Air Force test data were used to compare the different procedures for equating mental tests: conventional (equipercentile and linear), Item Response Theory (IRT), and strong true-score theory (STST); data collection designs used were single-group, equivalent-groups, and anchor test. Equating transformations were…

Two aspects of criterion referenced testing are discussed: cutting scores and test length. Several practices in determining passing scores are enumerated: (1) setting passing scores so that a predetermined percent of students pass; (2) inspecting each test item to determine how important it is that it be answered correctly; (3) determining the…

Goodness of fit of raw test score data were compared, using two latent trait models: the Rasch model and the Birnbaum three-parameter logistic model. Data were taken from various achievement tests and the Scholastic Aptitude Test (Verbal). A minimum sample size of 1,000 was required, and the minimum test length was 40 items. Results indicated that…