Preliminary evaluation of a testing technique which might meet the need for a standardized, validated, and objective means of psychologically testing people with visual or reading impairments is reported. The test is intended to be administered via an audiocassette, with identical administration and response procedures for totally and partially…

The reliability coefficient is predicted from the test information function (TIF) or two modified TIF formulas and a specific trait distribution. Examples illustrate the variability of the reliability coefficient across different trait distributions, and results are compared with empirical reliability coefficients. (SLD)

Discusses the exact meaning and limitations of commonly used types of standardized test scores: grade equivalent scores; percentile ranks, and standard scores. (SR)

A Bayesian alternative to interpretations based on classical reliability theory is presented. Procedures are detailed for calculation of a posterior score and credible interval with joint consideration of item sample and occasion error. (Author/SLD)

Includes an interview with a noted figure in the field of language assessment. Discusses his work on washback theory as well as his experiences with and views on the challenges and advantages of computer-based and Web-based testing. (Author/VWL)

This article focuses on Louis Guttman's contributions to the classical theory of educational and psychological tests, one of the lesser known of his many contributions to quantitative methods in the social sciences. Guttman's work in this field provided a rigorous mathematical basis for ideas that, for many decades after Spearman's initial work,…

Two new prophecy formulas for estimating item response theory (IRT)-based reliability of a shortened or lengthened test are proposed. Some of the relationships between the two formulas, one of which is identical to the well-known Spearman-Brown prophecy formula, are examined and illustrated. The major assumptions underlying these formulas are…

This article studies the ordinal reliability of (total) test scores. This study is based on a classical-type linear model of observed score (X), true score (T), and random error (E). Based on the idea of Kendall's tau-a coefficient, a measure of ordinal reliability for small-examinee populations is developed. This measure is extended to large…

The simple practice effects commonly observed when retaking general cognitive ability tests present a potential paradox. If observed score changes reflect real changes in g, we must revisit our understanding of its stability. Conversely, if observed score changes reflect something other than a true change in the underlying latent construct, this…

This paper analyzes the theoretical, pragmatic, and substantive factors that have hampered the integration between psychology and psychometrics. Theoretical factors include the operationalist mode of thinking which is common throughout psychology, the dominance of classical test theory, and the use of "construct validity" as a catch-all category…

A statistical test for detecting answer copying on multiple-choice items is presented. The test is based on the exact null distribution of the number of random matches between two test takers under the assumption that the response process follows a known response model. The null distribution can easily be generalized to the family of distributions…

Item response theory (IRT) methodology is introduced as a tool for improving assessment instruments used with people who have disabilities. Need for this approach in rehabilitation is emphasized; differences between IRT and classical test theory are clarified. Concepts essential to understanding IRT are defined, necessary data assumptions are…

A potential undesirable effect of multistage testing is differential speededness, which happens if some of the test takers run out of time because they receive subtests with items that are more time intensive than others. This article shows how a probabilistic response-time model can be used for estimating differences in time intensities and speed…

In many practical settings, essentially the same differential item functioning (DIF) procedures have been in use since the late 1980s. Since then, examinee populations have become more heterogeneous, and tests have included more polytomously scored items. This paper summarizes and classifies new DIF methods and procedures that have appeared since…

With increasing interest in studies evaluating treatment outcome in children with attention deficit hyperactivity disorder (ADHD), there is a need for treatment-sensitive instruments that are feasible, yield valid and reliable scores, and measure outcome in a "time-locked" and "situation- and symptom-specific" manner. These instruments are needed…