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The Accuracy and Consistency of a Series of IRT True Score Equatings
Author(s) -
Li Deping,
Jiang Yanlin,
von Davier Alina A.
Publication year - 2012
Publication title -
journal of educational measurement
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.917
H-Index - 47
eISSN - 1745-3984
pISSN - 0022-0655
DOI - 10.1111/j.1745-3984.2012.00167.x
Subject(s) - equating , statistics , item response theory , consistency (knowledge bases) , mathematics , econometrics , sample (material) , test score , sample size determination , psychometrics , standardized test , chemistry , geometry , chromatography , rasch model
This study investigates a sequence of item response theory (IRT) true score equatings based on various scale transformation approaches and evaluates equating accuracy and consistency over time. The results show that the biases and sample variances for the IRT true score equating (both direct and indirect) are quite small (except for the mean/sigma method). The biases and sample variances for the equating functions based on the characteristic curve methods and concurrent calibrations for adjacent forms are smaller than the biases and variances for the equating functions based on the moment methods. In addition, the IRT true score equating is also compared to the chained equipercentile equating, and we observe that the sample variances for the chained equipercentile equating are much smaller than the variances for the IRT true score equating with an exception at the low scores.