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The Circle‐Arc Method for Equating in Small Samples
Author(s) -
Livingston Samuel A.,
Kim Sooyeon
Publication year - 2009
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.1745-3984.2009.00084.x
Subject(s) - equating , resampling , statistics , mathematics , percentile , transformation (genetics) , econometrics , rasch model , biochemistry , chemistry , gene
This article suggests a method for estimating a test‐score equating relationship from small samples of test takers. The method does not require the estimated equating transformation to be linear. Instead, it constrains the estimated equating curve to pass through two pre‐specified end points and a middle point determined from the data. In a resampling study with two test forms that differed substantially in difficulty, the proposed method compared favorably with other equating methods, especially for equating scores below the 10th percentile and above the 90th percentile.