ERIC Number: EJ1069885
Record Type: Journal
Publication Date: 2015-Jul
Abstractor: As Provided
Reference Count: 23
Effect of Adjusting Pseudo-Guessing Parameter Estimates on Test Scaling When Item Parameter Drift Is Present
Han, Kyung T.; Wells, Craig S.; Hambleton, Ronald K.
Practical Assessment, Research & Evaluation, v20 n16 Jul 2015
In item response theory test scaling/equating with the three-parameter model, the scaling coefficients A and B have no impact on the c-parameter estimates of the test items since the cparameter estimates are not adjusted in the scaling/equating procedure. The main research question in this study concerned how serious the consequences would be if c-parameter estimates are not adjusted in the test equating procedure when item-parameter drift (IPD) is present. This drift is commonly observed in equating studies and hence, has been the source of considerable research. The results from a series of Monte-Carlo simulation studies conducted under 32 different combinations of conditions showed that some calibration strategies in the study, where the cparameters were adjusted to be identical across two test forms, resulted in more robust equating performance in the presence of IPD. This paper discusses the practical effectiveness and the theoretical importance of appropriately adjusting c-parameter estimates in equating.
Descriptors: Item Response Theory, Monte Carlo Methods, Scaling, Test Items, Guessing (Tests), Test Format, Equated Scores, Classification, Accuracy, Tests
Dr. Lawrence M. Rudner. e-mail: email@example.com; Web site: http://pareonline.net
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A