Measurement invariance of the strength of motivation for medical school: a multi-group confirmatory factor analysis

Table 6 Measurement invariance for scales across two independent samples

Scale	χ²	df	p	△χ² (p)	CFI	△CFI	TLI	SRMR	RMSEA	RMSEA 90% CI
F1
Step 1: Configural invariance	8.86	10	0.5446		1.00		1.00	0.02	0.00	[0.00, 0.05]
Step 2: Metric invariance	13.76	14	0.4676	−4.90 (0.0770)	1.00	0.00	1.00	0.03	0.00	[0.00, 0.04]
Step 3: Scalar invariance	16.78	18	0.5381	−3.02 (−0.0705)	1.00	0.00	1.00	0.03	0.00	[0.00, 0.04]
F2
Step 1: Configural invariance	25.37	10	0.0047		0.99		0.97	0.02	0.06	[0.03, 0.09]
Step 2: Metric invariance	29.20	14	0.0098	−3.83 (−0.0051)	0.99	0.00	0.98	0.03	0.05	[0.02, 0.07]
Step 3: Scalar invariance	33.97	18	0.0127	−4.77 (−0.0029)	0.99	0.00	0.99	0.04	0.04	[0.02, 0.07]
F3
Step 1: Configural invariance	21.91	8	0.0051		0.97		0.93	0.03	0.06	[0.03, 0.09]
Step 2: Metric invariance	27.44	12	0.0067	−5.53 (−0.0016)	0.97	0.00	0.95	0.04	0.05	[0.03, 0.08]
Step 3: Scalar invariance	30.28	16	0.0166	−2.84 (−0.0099)	0.97	0.00	0.96	0.04	0.04	[0.02, 0.07]

F1 willingness to sacrifice subscale, F2 readiness to start subscale, F3 persistence subscale CFI comparative fit index, TLI Tucker-Lewis Index, CI confidence interval, SRMR standardized root-mean-square residual, RMSEA root-mean-square error of approximation

ISSN: 1472-6920