Large sample standard errors for the Tucker method of linear equating under the common item nonrandom groups design are derived under normality assumptions as well as under less restrictive assumptions. Standard errors of Tucker equating are estimated using the bootstrap method described by Efron. The results from different methods are compared…

The purpose of this study was to empirically examine the relationship between violations of the assumption of unidimensionality, as assessed by the factor analysis of item parcel data, and the quality of item response theory (IRT) true-score equating, as measured by score scale stability. The verbal section of the Scholastic Aptitude Test (SAT)…

A formula is derived for the asymptotic standard error of a true-score equating by item response theory (IRT). The equating method is applicable when the two tests to be equated are administered to different groups along with an "anchor test." Numerical standard errors are shown for an actual equating 1) comparing the standard errors of…

For several years counselors have been interested in equating the ACT composite score with the SAT total score. This paper explores the possibility of using the first semester college grade point average as an anchor variable for equating the two tests. Research indicated that colleges should develop local conversion tables. (Author)

Presented are the methodology and results of an equipercentile equating study in which subtests of the following three editions of multiple aptitude test batteries, in widespread use in 1960, were equated to the tests of the Project TALENT test battery: Flanagan Aptitude Classification Tests (1957); Differential Aptitude Tests (1947) and; the…

Traditionally, comparable content-area forms and levels of a multi-level, multi-form achievement test series have been equated using the equipercentile method. There is some evidence to indicate, however, that better procedures are needed. A linking procedure is being used to equate simultaneously 40 different test forms of an achievement test:…

For two tests measuring the same trait, the program, BIV20, equates the scores using the two True score distributions estimated by the univariate method 20 program (see Wingersky, Lees, Lennon, and Lord, 1969) and, with these equated true scores and their distributions, estimates the bivariate distribution scores and the relative efficiency of the…

This paper looks at some of the problems arising from the procedures used by the Queensland, Australia, Board of Secondary School Studies to compile percentile scores known as Tertiary Entrance Scores. Although efforts to equate across schools and across subjects are being challenged, at present there is no alternative. (LMO)

The delta-plot method is used to identify which common items in a common item nonequivalent groups design for test equating show large changes in their p-values across administrations. Outliers in that plot denote differential item behavior and are candidates for exclusion from the common item pool. This study investigated whether keeping or…

This study investigated the practical effects of local item dependence (LID) on item response theory (IRT) true-score equating. A scenario was defined that emulated the Law School Admission Test (LSAT) preequating model, and data were generated to assess the impact of different degrees of LID on final equating outcomes. An extreme amount of LID…

This paper illustrates a method to study rater severity across exam administrations. A multi-facet Rasch model defined the ratings as being dominated by four facets: examinee ability, rater severity, project difficulty, and task difficulty. Ten years of data from administrations of a histotechnology performance assessment were pooled and analyzed…

Issues involved in linking the National Assessment of Educational Progress (NAEP) to the proposed Voluntary National Tests (VNTs) are discussed. Linkage is used to refer to procedures intended to permit scores from two different tests that are designed to measure the same variable to be expressed on the same scale. There are substantial…

This study investigated whether equating accuracy improves with an anchor test that is more representative of its corresponding total test and whether such content effect depends on the particular equating method used. Scoring outcomes of a professional examination for a medical specialty were used. A total of 1,092 examinees took one form, and…