I'm running a DSEM-CFA for my dissertation and trying to use Hamaker's syntax for examining differences in factor loadings across the between and within levels. However, I'm running into an issue with finding a consistently invariant item to use as the anchor item. I'm aware of a method for identifying invariant item sets by Cheung and Rensvold (1999), but given the more complex nature of DSEM, wanted to make sure that there are not better methods for identifying the best anchor item. Please advise!
To run a time-series model / DSEM model you must have more than one observation in each cluster, and in fact we would recommend at least 6 observations per person as you have 5 subject specific parameters.
As a first analysis I would recommend that you run a simpler model
%within% f by y1-y3(&1); f on f&1; f;
and exclude all clusters with 5 observations or less. You should also run the standard two level as a very first step