### CFA with a single factor ## Fit values for a CFA with a single factor can only be computed ## with models with more than 3 observed variables. ## With 3 obeserved variables and one factor you have to compute 6 free ## parameters (with one fixed). But your covariance matrix has also 6 ## nonredundant elements. Hence you get df=0 degress of freedom. ## A chi-squared distribution with df=0 is constant 0, hence we ## can expect the test statistic to be 0.