Tests of invariance for the proposed one-factor structure of the Client Satisfaction Questionnaire adapted to Internet-based interventions between sample 1 (N = 174) and sample 2 (N = 111): results of multigroup confirmatory factor analyses with MLR estimator.

Model	χ2	df a	χ2/ df	CFIb	RMSEAc	SRMRd
M1 configural invariance	99.2	40	2.5	.964	.102	.031
M2 weak invariance	104.5	47	2.2	.965	.093	.043
M3 strong invariance	120.2	54	2.2	.959	.093	.048
M4 partial strong invariance	111.3	53	2.1	.964	.088	.045

^adf: degrees of freedom.

^bCFI: comparative fit index.

^cRMSEA: root-mean-square error of approximation.

^dSRMR: standardized root-mean-square residual.