Since the invention of z-scores (standardized scores), comparison among different tests has been widely conducted by test developers, instructors, educational researchers, and psychometricians. Equating, calibration, and moderation are terms used to describe broad levels of possible comparison among educational assessments (Dorans, 2004; Feuer, Holland, Green, Bertenthal, & Hemphill, 1999; Linn...

von Davier, Holland and Thayer (2004) laid out a five-step framework of test equating which can be applied to various data collection designs and equating methods. In the continuization step, they present an adjusted Gaussian kernel method which preserves the first two moments. This paper proposes an alternative continuization method which directly uses the log-linear function from the smoothin...

A Markov chain Monte Carlo (MCMC) method and a bootstrap method were compared in the estimation of standard errors of item response theory (IRT) true score equating. Three test form relationships were examined: parallel, tauequivalent, and congeneric. Data were simulated based on Reading Comprehension and Vocabulary tests of the Iowa Tests of Basic Skills1. For parallel and congeneric test form...

Frequency estimation (also called post-stratification) is an equating method employed under the common-item nonequivalent groups design. A modified frequency estimation method is proposed here, based on altering one of the traditional assumptions in frequency estimation in order to correct for equating bias. A simulation study was carried out to compare equating errors for the modified frequenc...