Improving Item Response Theory Model Calibration by Considering Response Times in Psychological Tests

Research findings indicate that response times in personality scales are related to the trait level according to the so-called speed-distance hypothesis. Against this background, Ferrando and Lorenzo-Seva proposed a latent trait model for the responses and response times in a test. The model consists of two components, a standard item response model and a supplemental response time model. The authors could demonstrate that the consideration of response time increases the precision of trait estimation. However, the use of the model is not limited to trait estimation. The consideration of response time additionally enhances the calibration of the item response model. Due to limitations of the suggested estimation method for model calibration, Ferrando and Lorenzo-Seva were not able to exploit this additional benefit of response time modeling. In the article, an improved estimation method is proposed that is faster and more efficient than the original approach. It can be shown that the standard deviation of the parameter estimates of the item response model can be reduced up to 25% when applying the new method.