This article reviews three topics from test theory that continue to raise discussion and controversy and capture test theorists' and constructors' interest. The first topic concerns the discussion of the methodology of investigating and establishing construct validity; the second topic concerns reliability and its misuse, alternative definitions…

Educational and psychological tests are often composed of multiple short subtests, each measuring a distinct latent trait. Unfortunately, short subtests suffer from low measurement precision, which makes the bandwidth-fidelity dilemma inevitable. In this study, the authors demonstrate how a multidimensional Rasch analysis can be employed to take…

Develops a statistical test for the hypothesis that alpha'(1) =alpha'(2) when alpha'(1) is the Spearman-Brown extrapolated value of Cronbach's alpha reliability for test 1 and alpha'(2) is the unadjusted coefficient for test 2. The test is shown to exercise tight control of Type I error. (Author/SLD)

Short tests containing at most 15 items are used in clinical and health psychology, medicine, and psychiatry for making decisions about patients. Because short tests have large measurement error, the authors ask whether they are reliable enough for classifying patients into a treatment and a nontreatment group. For a given certainty level,…

Kelly's formula estimates sampling variance of correlation corrected for attenuation by using split-half reliabilities. In some cases, coefficient alpha estimate of reliability is preferable. A simulation study suggests a variation of Kelly's formula can be used appropriately with coefficient alpha. Kelly's formula is modified to accept…

Examined the effects of test length and sample size on the alternate forms reliability and equating of simulated mathematics tests composed of constructed response items scaled using the two-parameter partial credit model. Results suggest that, to obtain acceptable reliabilities and accurate equated scores, tests should have at least 8 6-point…

This paper presents a method for estimating the accuracy and consistency of classifications based on test scores. The scores can be produced by any scoring method, including the formation of a weighted composite. The estimates use data from a single form. The reliability of the score is used to estimate its effective test length in terms of…

Undergraduate psychology examinations from 48 schools were analyzed to determine the proportion of items at each level of Bloom's Taxonomy, item format, and test length. Analyses indicated significant relationships between item complexity and test length even when taking format into account. Use of higher items may be related to shorter tests,…

Monte Carlo methods are used to evaluate marginal maximum likelihood estimation of item parameters and maximum likelihood estimates of theta in the two-parameter logistic model for varying test lengths, sample sizes, and assumed theta distributions. Results with 100 datasets demonstrate the methods' general precision and stability. Exceptions are…