parameter estimation for finite mixtures of generalized partial credit models
We consider a finite length test and assume that each item has m?2 graded response categories which satisfy the Generalized Partial Credit Model ( GPCM ) from the Item Response Theory and also that there exist K population classes. We give a parameter estimation procedure for this finite GPCM mixture, based on the EM algorithm and test the model with simulated data. The paper contains complete derivation of the basic model formulas.
generalized partial credit model item response theory em algorithm