Four-parameter Item Response Model Incorporating Response Time

Item response theory that developed in these years is the complete and advancededucational and psychological measurement theory. It is widely used in thepsychological measurement.Based on item response theory, in this paper, we present a four-parameter itemresponse model that incorporates response time, and then illustrate the modelparameters estimation and EM algorithms. Finally, the model is simulated under a realexam, which320examinees take the test. We analysed the results detailedly and theability of the examinees is estimated.