Abstract:

Abstract: The Three-Parameter Logistic (3PL) model have some advantages over the other Item Response Theory (IRT) models for multiple-choice testing. Under the 3PL model, an examinee with no knowledge can correctly answer an item at the probability of the value of the c-parameter. The propensity for the guessing effect is the same for all ability levels under 3PL models. However, the idea of ability-based guessing has been asserted. In this study, different IRT models for which the guessing parameters are considered in different ways were elaborated. Also, the IRT models were compared with each other via a simulation study and an empirical data set. The results were compared based on item parameter estimation bias and RMSE. Based on the results, the FG3PL model gave the worst results (i.e., larger bias and RMSE) compared to other models. C3PL model was fine when the simulated data were generated by the 2PL model, but not by 3PL data.

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