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The Cureton-Tukey Method of Equating Test Scores

Karon, Bertram P.; Cliff, Rosemary Hayes
Publication Year:
Report Number:
ETS Research Bulletin
Document Type:
Page Count:
Subject/Key Words:
Cureton-Tukey Method, Equated Scores, Equipercentile Equating, Mean and Sigma Method, Statistical Bias


Because of its less restrictive assumptions, the equi-percentile method of equating is theoretically preferable to the mean-and-sigma method; unfortunately it involves more sampling error. The Cureton-Tukey procedure for reducing this sampling error by mathematically "smoothing" the samples before equating by the equi-percentile method is described, and empirically evaluated. Although the Cureton-tukey procedure seems promising, none of the differences among the three methods being compared -- the mean-and-sigma method, the equi-percentile method, and the Cureton-Tukey method -- reach statistical significance. It is therefore impossible to draw any definitive conclusions from the limited data employed in this study.

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