ERIC Number: EJ1030021
Record Type: Journal
Publication Date: 2014
Abstractor: As Provided
Reference Count: 34
Evaluating Equating Accuracy and Assumptions for Groups that Differ in Performance
Powers, Sonya; Kolen, Michael J.
Journal of Educational Measurement, v51 n1 p39-56 Spr 2014
Accurate equating results are essential when comparing examinee scores across exam forms. Previous research indicates that equating results may not be accurate when group differences are large. This study compared the equating results of frequency estimation, chained equipercentile, item response theory (IRT) true-score, and IRT observed-score equating methods. Using mixed-format test data, equating results were evaluated for group differences ranging from 0 to 0.75 standard deviations. As group differences increased, equating results became increasingly biased and dissimilar across equating methods. Results suggest that the size of group differences, the likelihood that equating assumptions are violated, and the equating error associated with an equating method should be taken into consideration when choosing an equating method.
Descriptors: Accuracy, Equated Scores, Differences, Groups, Comparative Analysis, Item Response Theory, Computation, Methods, Bias
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A