Large-scale Assessments in Education

An IERI – International Educational Research Institute Journal

Table 4 Relative model fit statistics (PE-GH) for unidimensional (1D) and multidimensional (MD) models

From: Assessment of fit of item response theory models used in large-scale educational survey assessments

Model	LTT math age 9	Reading grade 12	Math grade 8	Science grade 12
1D 1PL/PCM	0.465	0.634	0.607	0.643
1D 2PL/GPCM	0.456	0.629	0.601	0.636
1D C3PL/GPCM	0.455	0.629	0.600	0.634
1D 3PL/GPCM	0.454	0.629	0.600	0.634
MD 3PL/GPCM	–	0.628^a	0.600^b	–

^aThree-dimensional model
^bFive-dimensional model

Back to article page