As item response theory (IRT) has developed and is widely applied, investigating the fit of a parametric model becomes an important part of the measurement process when implementing IRT. The usefulness and successes of IRT applications rely heavily on the extent to which the model reflects the...

Based on Kamatas item analysis model (2001), an extension for differential item functioning procedure was developed and the applicability was examined. The Kamatas item analysis model is a type of hierarchical generalized linear model for item analysis, in which items are considered as nested in...