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A Large-Scale Evaluation of Linear and Curvilinear Score Equating Models, Volumes I and II SAT TSWE

Marco, Gary Lee.; Petersen, Nancy S.; Stewart, E. Elizabeth
Publication Year:
Report Number:
ETS Research Memorandum
Document Type:
Page Count:
Subject/Key Words:
Equated Scores, Mathematical Models, Models, Scholastic Aptitude Test (SAT), Scoring, Statistical Analysis, Test of Standard Written English (TSWE)


The purpose of this study was to examine the adequacy of various linear and curvilinear score equating models when certain sample and test characteristics were systematically varied. Linear, equipercentile (direct and indirect through frequency estimation), and item characteristic curve (one- and three-parameter logistic) equating models were evaluated. ETS computer files for the April 1975 and November 1975 administrations of the SAT and the Test of Standard Written English provided the data for the study. The three-parameter logistic model was found to be most consistently accurate.

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