ERIC Number: ED249242
Record Type: Non-Journal
Publication Date: 1984-Jun
Reference Count: N/A
A Comparative Study of Methods of Equating TOEFL Test Scores.
Hicks, Marilyn M.
Six methods of equating Test of English as a Foreign Language (TOEFL) test scores for samples consisting of the usual groups of examinees and groups controlled for native language representation were evaluated in terms of scale stability. The equating methods included three item response theory (IRT) variants (fixed b's scaling, a one-parameter model in which a- and c-parameters were fixed at constant values, and a model in which all three parameters were re-estimated), and three conventional equating methods (Tucker, Levine and Equipercentile). The equating methods were applied to Section II, Structure and Written Expression, and Section III, Reading Comprehension and Vocabulary. For the regular group of examinees, fixed b's IRT equating exhibited the greatest scale stability for both sections with the one-parameter IRT model and Tucker linear equating following in that order. For most equating methods, controlling for native language resulted in increased scale stability relative to the regular group for Section II, but produced more error in Section III. This interaction may be related to the differential performance observed among language groups on Section III in previous studies. Results supported continued use of fixed b's scaling for TOEFL data using a random sample of examinees from the total testing group. (Author)
Descriptors: College Entrance Examinations, Comparative Analysis, English (Second Language), Equated Scores, Language Tests, Latent Trait Theory, Measurement Techniques, Sampling, Scaling, Statistical Analysis, Test Interpretation, Test Items, Testing Problems
Educational Testing Service, Research Publications, R-116, Princeton, NJ 08541
Publication Type: Reports - Research
Education Level: N/A
Authoring Institution: Educational Testing Service, Princeton, NJ.
Identifiers - Assessments and Surveys: Test of English as a Foreign Language