In this study, we investigated whether preequating results agree with equating results that are based on observed operational data (postequating) for a college placement program. Specifically, we examined the degree to which item response theory (IRT) true score preequating results agreed with those from IRT true score postequating and from…

This report builds on and extends existent research on population invariance to new tests and issues. The authors lay the foundation for a deeper understanding of the use of population invariance measures in a wide variety of practical contexts. The invariance of linear, equipercentile and IRT equating methods are examined using data from five…

A procedure is described for estimating the reliability and conditional standard errors of measurement of scale scores incorporating the discrete transformation of raw scores to scale scores. The method is illustrated using a strong true score model, and practical applications are described. (SLD)