A simple stochastic model is formulated in order to determine the optimal time between the first test and the second test when the test-retest method of assessing reliability is used. A forgetting process and a change in true score process are postulated. Some numerical examples and suggestions are presented. (Author/JKS)

Bond criticized the base-free measure of change proposed by Tucker, Damarin, and Messick by pointing to an incorrect derivation which is here viewed instead as a correct derivation entailing an inadequately specified assumption. Bond's revision leads to negatively biased estimates, whereas the original approach leads to unbiased estimates.…

Gives an account of classical test theory that shows how it can be viewed as a mean and variance approximation to a general version of item response theory and then shows how this approach can give insight into predicting the true score of a test and the true scores of tests not necessarily parallel to the given test. (SLD)

Test homogeneity and internal consistency reliability indices were developed on the basis of theoretical considerations of properties of hierarchical structures of data matrices. This reconceptualization, in terms of ordinal test theory, has potential for explication of the mutual relationship of test reliability and homogeneity. (TJH)

Study compares Wechsler (WISC-R) profiles of special-education students to seven core types distinguished primarily by levels of global ability. More than 96% of these students were found to be similar to one of the core types considered to be common variants of normal intellectual ability. Based on data, it is recommended that "no way"…

Provides a general mathematical framework is provided that can be specialized to four different reliability coefficients. Consideration of this general framework makes it easier to convey to students the individual character of the formulations of reliability and the extent of their underlying similarity. (SLD)

This paper explains how different factors affect classical reliability estimates, such as test-retest, interrater, internal consistency, and equivalent forms coefficients. The limitations of classical test theory are explored, and the advantages of generalizability theory are discussed. Concrete examples are used. (SLD)

Evaluated coefficient alpha under violations of two classical test theory assumptions: essential tau-equivalence and uncorrelated errors through simulation. Discusses the interactive effects of both violations with true and error scores. Provides empirical evidence of the derivation of M. Novick and C. Lewis (1993). (SLD)

People use external knowledge representations (EKRs) to identify, depict, transform, store, share, and archive information. Learning how to work with EKRs is central to becoming proficient in virtually every discipline. As such, EKRs play central roles in curriculum, instruction, and assessment. Five key roles of EKRs in educational assessment 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…

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…

The theory of score validity has undergone several revisions within the measurement community. The current consensus among professionals is a rejection of the trinitarian doctrine (J. P. Guion, 1980) of score validity and the recognition of a unified view that includes social consequences of test interpretation and use. While some aspects of the…

Generalizability theory provides a technique for accurately estimating the reliability of measurements. The power of this theory is based on the simultaneous analysis of multiple sources of error variances. Equally important, generalizability theory considers relationships among the sources of measurement error. Just as multivariate inferential…

The purpose of this essay is to describe the principles of educational measurement proposed by B. Wood during the 1920s in his dissertation, written under the direction of E. L. Thorndike, and later published as "Measurement in Higher Education" (1923). These principles were selected because they illustrate one of the earliest and most complete…