Table 3.

Tests of longitudinal measurement invariance between the urban and rural groups for preference of solitude.

Model	χ 2	df	RMSEA	CFI	TLI	χ 2	Δχ2	Δdf	p
Model fit before allowing residuals of items to covary
M1	887.865	372	0.060	0.904	0.891	–	–	–	–
M2	915.866	390	0.059	0.902	0.894	M2 vs. M1	26.377	18	0.091
M3	950.390	411	0.058	0.899	0.897	M3 vs. M2	31.890	21	0.061
Model fit after allowing residuals of two items to covary a
M1	741.279	366	0.051	0.930	0.919
M2	767.888	384	0.051	0.928	0.921	M2 vs. M1	25.138	18	0.121
M3	803.364	405	0.050	0.926	0.923	M3 vs. M2	34.331	21	0.033

M1, Configural invariance; M2, Metric invariance; M3, Scalar invariance.

^aResiduals of the two items “I enjoy being by myself” and “I like spending time alone in my room” were allowed to covary according to model modification index.