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ERIC Number: ED359239
Record Type: Non-Journal
Publication Date: 1993-Apr
Pages: 52
Abstractor: N/A
Reference Count: N/A
Item Parameter Drift in IRT-Based Licensure Examinations.
Sykes, Robert C.; Ito, Kyoko
The purpose of this study was to investigate whether systematic, non-zero differences between pairs of item bank b-values have occurred in the recent history of two licensure examinations. Licensing examinations were studied for two related health care professions (Program 1 and Program 2). A series of analysis of covariance models was fit to the data in order to investigate the magnitude of changes in item bank b-values and the relationship of any changes to variables indexing factors that have been documented to affect the stability of item parameters. For Program 1, one 300-item form was used, and for Program 2, two 203-item forms were used to obtain a larger number of items. Analyses were first performed to evaluate the relationship, if any, between the dependent variable and the covariates. For both examinations, b-value differences across pairs of item administrations were not influenced by the changing position of the item in different forms. There were systematic changes as a function of time elapsed from a baseline, as discussed in the paper. Item parameter or scale drift was noted for one examination, while bank or pool drift was found for both. Factors that moderated bank drift, and differences between actual form cutscores and cutscores adjusted for documented bank and scale drift ranged from one to five points for the two examinations. Nine tables and five figures present details of the analyses. (SLD)
Publication Type: Reports - Evaluative; Speeches/Meeting Papers
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A