The Influence of Testlet Effect on the Accuracy of Parameter Estimation
2009
Hochschulschrift
Zugriff:
97
This research investigated the influence of testlet effect on the recovery of item and person parameters. Simulated data was used to compare the parameter recovery given by the traditional item response theory (IRT) model, the testlet response theory (TRT) model and the bi-factor model. And the Q3 index was computed for all the data sets to serve as a tool for local item dependence detection. Three testlet slope (0.0, 0.6, & 1.2), two sample sizes (500 & 1000 examinees) were manipulated for simulating the item response vectors. For each combination of the above conditions, there were 100 replications. The main findings are the following : 1.The accuracy of item parameter recovery was higher for the testlet-based models than that of traditional item-based model (i.e., 3PL model). Among the three models used, the TRT model performs best, followed by the bi-factor model and then the IRT model. 2.The greater sample size is, the better accuracy of item parameter recovery we gain. The greater testlet slope is, the greater estimation error is. 3.The Q3 index under all three models has decent detection capability on item local dependency. The performance of the Q3 index is nearly the same in all three models.
Titel: |
The Influence of Testlet Effect on the Accuracy of Parameter Estimation
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Autor/in / Beteiligte Person: | Lai, Pei-ling ; 賴佩伶 |
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Veröffentlichung: | 2009 |
Medientyp: | Hochschulschrift |
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