Measurement Invariance and Psychometric Analysis of Oxford Happiness Inventory Scale across Gender and Marital Status

Table 2

Test statistics of comparison of different IRT models.

	RSM	GPCM	GRM
RSM	-14402.06
GPCM	1158.254	-13822.93
GRM	1319.515	161.261	-13742.30

Notes: value ≤0.001; Main diagonal: log-likelihood values; Off-diagonal: chi-square test of model comparison.