Publications & Resources

An Alternative IRT Observed Score Equating Method

Feb 2009

Taehoon Kang and Troy T. Chen

In this report, an alternative item response theory (IRT) observed score equating method was newly developed. The proposed equating method was illustrated with two real data sets and the equating results were compared to those of traditional IRT true score and IRT observed score equating methods. Using three loss indices, the new method appeared to produce equating equivalents more similar to those of the IRT observed score equating than those of the IRT true score equating. In addition to the conversion relationships between new form scores and their equating equivalents on the old form scale, the bootstrap standard errors of equating were provided and compared for the three IRT equating methods. These methods performed similarly.

Kang T., & Chen, T. T. (2009). An alternative IRT observed score equating method (CRESST Report 751). Los Angeles: University of California, Los Angeles, National Center for Research on Evaluation, Standards, and Student Testing (CRESST).