Examines the effects of four parameters on the accuracy of test equating under a relaxed definition of test form equivalence. The four parameters studied were sample size, test form length, test form reliability, and the correlation between true scores of the test forms to be equated. (CK)

The consequences of the assumption that the expected score is equal to the true score are shown and alternatives discussed. (MS)

Tucker, Damarin, and Messick proposed a "base-free" measure of change which involves the computation of residual scores that are uncorrelated with true scores on the pretest. The present note discusses this change measure and demonstrates that properties they attribute to a are, in fact, properties of b. (Author/CTM)

Reliability maximizing weights are related to theoretically specified true score scaling weights to show a constant relationship that is invariant under separate linear tranformations on each variable in the system. Test theoretic relations should be derived for the most general model available and not for unnecessarily constrained models.…

Using a new coefficient, a rescaling of the Bayes risk is examined and a modification of this coefficient is described which yields an index that always has a value between zero and one. (Author/MH)

Proposes formulas for expected true-score measures and reliability of binary items as a function of their Rasch difficulty when the trait (ability) distribution is normal or logistic. Provides an illustrative example for using the proposed formulas. (SLD)

Dynamic generalizations of reliability and validity that will incorporate longitudinal or developmental models, using latent curve analysis, are discussed. A latent curve model formulated to depict change is incorporated into the classical definitions of reliability and validity. The approach is illustrated with sociological and psychological…

This paper argues that: test data are ordinal; latent trait scores are only determined ordinally; and test data are used largely for ordinal purposes. A set of ordinal assumptions is presented, including an ordinal version of local independence. It is concluded that a purely ordinal test theory is possible. (TJH)

Negative coefficients of reliability, sometimes returned by the standard formula for estimation of the internal-consistency reliability, are neither theoretically nor numerically correct. Alternative strategies for test development in this special case are suggested. (Author)

Proposes a new regression correction for the SIBTEST statistical tests (R. Shealy and W. Stout, 1993) that essentially uses a two-segment piecewise linear regression of the true on observed matching subtest scores. A simulation study illustrates the approach. (SLD)

In educational testing, subscores may be provided based on a portion of the items from a larger test. One consideration in evaluation of such subscores is their ability to predict a criterion score. Two limitations on prediction exist. The first, which is well known, is that the coefficient of determination for linear prediction of the criterion…

This study aimed at estimating the correlation between true scores (true consistency) of vocational interest over a short time span in a sample of 1089 adults. Participants were administered 54 items assessing vocational, family, and leisure interests twice over a 1-month period. Responses were analyzed with a multitrait (MT) model, which supposes…

A sequence of simulations was carried out to aid in the diagnosis and interpretation of equating differences found between random and matched (nonrandom) samples for four commonly used equating procedures: (1) Tucker linear observed-score equating; (2) Levine equally reliable linear observed-score equating; (3) equipercentile curvilinear…

A model is proposed for the description of ordinal test scores based on the definition of true score as expected rank; its deviations are compared with results from classical test theory. An unbiased estimator of population true score from sample data is calculated. Score variance and population reliability are examined. (Author/BJG)