Comparing Different Test Equating Methods Based on Equity Property

The purpose of this study was to compare the performance of three equipercentile and two item response theory (IRT) equating methods based on equity property. In this study, the social science test scores of Booklet A and Booklet C from 2009 the Assessment of Student Achievement were equated under equivalent groups design. The study group consisted of 15.173 and 14.365 9th grade students which took Booklet A and Booklet C. The equity property was evaluated based on first-order equity (FOE) which requires the same conditional means after equating and second-order equity (SOE) which requires the same conditional error of measurement. Results showed that IRT true score equating method best preserved FOE property and IRT observed score equating method best preserved SOE property.