Goodness-of-fit indices for the different models and chi-square differences between the models.

RMSEA = root mean square error of approximation; 90% CI = 90% confidence interval of the RMSEA; CFI = comparative fit index; TLI = Tucker Lewis Index, AIC = Akaike Information Criterion, df = degrees of freedom.aAll parameters are assigned to be equal for all four groups.bFactor loadings are assigned to be equal for all four groups.cAll parameters can vary between all four groups.dComparison between models 1 and 2.eComparison between models 2 and 3.