Hi, I am trying to run CFAs with 2 and 3 factors and 14 indicators. I get the following warning message:
WARNING: THE RESIDUAL COVARIANCE MATRIX (THETA) IS NOT POSITIVE DEFINITE. THIS COULD INDICATE A NEGATIVE VARIANCE/RESIDUAL VARIANCE FOR AN OBSERVED VARIABLE, A CORRELATION GREATER OR EQUAL TO ONE BETWEEN TWO OBSERVED VARIABLES, OR A LINEAR DEPENDENCY AMONG MORE THAN TWO OBSERVED VARIABLES. CHECK THE RESULTS SECTION FOR MORE INFORMATION. PROBLEM INVOLVING VARIABLE IPQ3.
And the following estimates in the R2 section of the output:
You have a negative residual variance for IPQ3. This makes the model inadmissible. For a continuous variable, if the value is small and insignificant, you can fix the residual variance to zero. With a categorical item, the residual variance is not a model parameter so you can't fix the residual variance to zero. You need to change the model or not use that item.