Sampling theory for the intraclass reliability coefficient, a Spearman-Brown extrapolation of alpha to a single measurement for each examinee, is less recognized and less cited than that of coefficient alpha. Techniques for constructing confidence intervals and testing hypotheses for the intraclass coefficient are presented. (SLD)

An approximate statistical test of the equality of two intraclass reliability coefficients based on the same sample of people is derived. Such a test is needed when a researcher wishes to compare the reliability of two measurement procedures, and both procedures can be applied to results from the same group. (SLD)

Rigorous comparison of the reliability coefficients of several tests or measurement procedures requires a sampling theory for the coefficients. This paper summarizes the important aspects of the sampling theory for Cronbach's (1951) coefficient alpha--a widely used internal consistency coefficient. This theory enables researchers to test a…

Estimating the reliability of measures derived from separate questions on essay tests or individual judges on a rater panel is considered. Cronbach's alpha is shown to underestimate reliability in these cases. Some alternative coefficients are presented. (JKS)

An approximate statistical test is derived for the hypothesis that the intraclass reliability coefficients associated with two measurement procedures are equal. Control of Type 1 error is investigated by comparing empirical sampling distributions of the test statistic with its derived theoretical distribution. A numerical illustration is…

The net effect of the conditions under which tests are taken was empirically investigated using the scores obtained by high school students on an English and a mathematics test. (Author/BB)

In some settings, the validity of a battery composite or a test score is enhanced by weighting some parts or items more heavily than others in the total score. This article describes methods of estimating the total score reliability coefficient when differential weights are used with items or parts.

The Feldt-Gilmer congeneric reliability coefficients make it possible to estimate the reliability of a test composed of parts of unequal, unknown length. The approximate standard errors of the Feldt-Gilmer coefficients are derived via a method using the multivariate Taylor's expansion. Monte Carlo simulation is employed to corroborate the…

This paper considers, from a theoretical point of view, two measurement approaches used in measuring success and failure in skills tests in physical education. The first, "fixed length" (FL) testing, entails counting the number of successful performances in a fixed number of trials. The second, "trials-to-criterion" (TTC)…

The reliabilities of two types of measurement plans were compared across six hypothetical distributions of true scores or abilities. The measurement plans were: (1) fixed-length, where the number of trials for all examinees is set in advance; and (2) trials-to-criterion, where examinees must keep trying until they complete a given number of trials…

A brief discussion of the concept of validity, a description of the nature and purposes of the Iowa Tests of Educational Development (ITED), and a rationale for the inclusion of ITED results as part of the overall program evaluation of a secondary school are presented. According to the authors, the ITED can validly be used as one of the…