

Measurement invariance across both gr... 

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Dear Mr. and Mrs. Muthen, I'm doing a longitudinal study and try to test for measurement invariance. For this, I took Little's (2013) approach and added the constraints simultaneously to both groups and measurement times. Consequently, for strict factorial invariance I constrained the intercepts of all observed variables, but there I faced the problem, that I could not estimate the latent factor means. For group 1, the estimates for both time points are constrained to 0; I could only estimate the latent mean differences for group 2. However, this model seems too restrictive since it doesn't allow the mean at time 2 for group 1 to vary. Is there any way to solve this. Thank you very much in advance. 


My mistake  meant "strong factorial invariance" 


With 2 groups and 2 time points you fix the factor mean to zero in only 1 of the 4 cases, e.g. for the control group at time 1. 


I tried to do that, however I haven't managed to estimate the factor mean at time2 for group 1. model: TIME1 by t1 t2 (1) t3 (2) t4 (3) t5 (4); TIME2 by t1_2 t2_2 (1) t3_2 (2) t4_2 (3) t5_2 (4); [t1@0 t1_2@0]; [t2 t2_2] (int1); [t3 t3_2] (int2); [t4 t4_2] (int3); [t5 t5_2] (int4); [TIME1@0]; [TIME2*]; model control: [TIME1*]; [TIME2*]; 


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