An analytic procedure for smoothing in equipercentile equating using cubic smoothing splines is described and illustrated. The effectiveness of the procedure is judged by comparing the results from smoothed equipercentile equating with those from other equating methods using multiple cross-validations for a variety of sample sizes. (Author/JKS)

The metric of the multidimensional item response theory (MIRT) item parameter estimates is usually referred to as reference axes that are orthogonal and of unit length. This is due to the fact that most MIRT parameter estimation programs solve the identification problem by requiring that multidimensional abilities be distributed as multivariate…

Item response theory (IRT) item parameters can be estimated using data from a common item equating design either separately for each form or concurrently across forms. This paper reports the results of a simulation study of separate versus concurrent item parameter estimation. Using simulated data from a test with 60 dichotomous items, 4 factors…

The functions, goals, and characteristics of test standardization are discussed, including an explanation of how score equating as an aspect of standardization is essential to the achievement of equity in testing. Psychometric specialists and testing program directors must understand score equating to ensure equitable use of tests. (Author/AL)

Presents 17 rules of thumb to create surveys that are likely to provide data of high enough quality to meet the requirements for measurement specified in a probabilistic conjoint measurement model. Use of these steps should allow the survey to be joined with others measuring the same variable to ensure continued equating with a single reference…

Studied the degree to which equating functions failed to demonstrate population invariance across subpopulations, using two root-mean-square difference measures of the degree to which functions used to link two tests computed on subpopulations differ from the linking function for the whole population. Illustrated the ideas using data from the…

Examined the effect of test purification in detecting differential item functioning (DIF) by means of polytomous extensions of the Raju area measures (N. Raju, 1990) and the Lord statistic (F. Lord, 1980). Simulation results suggest the necessity of using a two-stage equating purification process with the Raju exact measures and the Lord statistic…

Meehl's taxometric method was developed to distinguish categorical and continuous constructs. However, taxometric output can be difficult to interpret because expected results for realistic data conditions and differing procedural implementations have not been derived analytically or studied through rigorous simulations. By applying bootstrap…

This paper discusses loglinear models for assessing differential item functioning (DIF). Loglinear and logit models that have been suggested for studying DIF are reviewed, and loglinear formulations of the logit models are given. A polynomial loglinear model for assessing DIF is introduced. Two examples using the polynomial loglinear model for…

Test disclosure legislation in New York State (LaValle Act) has had a major impact on the national testing programs administered by Educational Testing Services (ETS) for various sponsoring organizations. The paper reviews the immediate operational effects of test disclosure in the following areas: (1) increase in number of test forms developed;…

The effectiveness of smoothing in reducing random errors in equipercentile equating of a short writing assessment with two raters, two prompts, with scores ranging from zero to five was examined. Thirteen methods were examined: no equating, three presmoothing, three postsmoothing, three combination presmoothing and postsmoothing, mean equating,…

The term "equating" refers to a statistical procedure that adjusts test scores on different forms of the same examination so that scores can be interpreted interchangeably. This study examines the impact of equating with fewer items than originally planned when items have been removed from the equating set for a variety of reasons. A…

The problems of standardized testing are considered, and the efforts of New York State legislators to change current practices in test usage are recounted. (LH)

The sample invariant properties of five anchor test equating methods are addressed. Equating results across two sampling conditions--representative sampling and new-form matched sampling--are compared for Tucker and Levine equally reliable linear equating, item response theory true-score equating, and two equipercentile methods. (SLD)

Different data imputation techniques that are useful for equipercentile equating are discussed, and empirical data are used to evaluate the accuracy of these techniques as compared with chained equipercentile equating. The kernel estimator, the EM algorithm, the EB model, and the iterative moment estimator are considered. (SLD)