The purpose of this simulation study was to assess the accuracy of a classical test theory (CTT)-based procedure for estimating the alternate-forms reliability of scores on a multistage test (MST) having 3 stages. We generated item difficulty and discrimination parameters for 10 parallel, nonoverlapping forms of the complete 3-stage test and…

In this study, I investigated 2 procedures intended to create test-taker groups of equal ability by poststratifying on a composite variable created from demographic information. In one procedure, the stratifying variable was the composite variable that best predicted the test score. In the other procedure, the stratifying variable was the…

A series of resampling studies was conducted to compare the accuracy of equating in a common item design using four different methods: chained equipercentile equating of smoothed distributions, chained linear equating, chained mean equating, and the circle-arc method. Four operational test forms, each containing more than 100 items, were used for…

This study examines how closely the kernel equating (KE) method (von Davier, Holland, & Thayer, 2004a) approximates the results of other observed-score equating methods--equipercentile and linear equatings. The study used pseudotests constructed of item responses from a real test to simulate three equating designs: an equivalent groups (EG)…

For tests used to make pass/fail decisions, the relevant standard error of measurement (SEM) is the SEM at the passing score. If the test is highly stratified, this SEM should be estimated by a split-halves approach. A formula and its derivation are provided. (Author)

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…

The standard error of measurement (SEM) is a measure of the inconsistency in the scores of a particular group of test-takers. It is largest for test-takers with scores ranging in the 50 percent correct bracket; with nearly perfect scores, it is smaller. On tests used to make pass/fail decisions, the test-takers' scores tend to cluster in the range…

A distinction is made between reliability of measurement and reliability of classification; the "criterion-referenced reliability coefficient" describes the former. Application of this coefficient to the probability distribution of possible scores for a single student yields a meaningful way to describe the reliability of a single score. (Author)

The traditional reliability coefficient and standard error of measurement are not adequate measures of reliability for tests used to make pass/fail decisions. Answering the important reliability questions requires estimation of the joint distribution of true and observed scores. Lord's "Method 20" estimates this distribution without the…

Besides the ubiquitous Pearson product-moment r, there are a number of other measures of relationship that are attenuated by errors of measurement and for which the relationship between true measures can be estimated. Among these are the correlation ratio (eta squared), Kelley's unbiased correlation ratio (epsilon squared), Hays' omega squared,…

This article is a reply to a previous paper (see TM 500 488) interpreting Livingston's original article (see TM 500 487). (CK)

Procedures are described for studying the reliability of decisions based on specific passing scores with tests made up of discrete items and designed to measure continuous rather than categorical traits. These procedures are based on the estimation of the joint distribution of true scores and observed scores. (CTM)

A reliability coefficient for criterion-referenced tests is developed from the assumptions of classical test theory. The coefficient is based on deviations of scores from the criterion score, rather than from the mean. (Author/CK)

This paper deals with test fairness regarding a test consisting of two parts: (1) a "common" section, taken by all students; and (2) a "variable" section, in which some students may answer a different set of questions from other students. For example, a test taken by several thousand students each year contains a common multiple-choice portion and…