Hello!

I'm attempting to fit a partial credit model to a set of data (Conquest 4). 73 students rated 37 statements with a 6-point likert scale. Due to category sparseness in the response vector, I collapsed the 6 categories into three.

When I attempt to fit the model, I get the error code in the subject line. Attached here is a screenshot showing this. Also, I've attached the command, data, and labels files.

Could this have to do with the fact that by collapsing the categories many of the response sequences are perfect scores (e.g., now, something like 45% of the response sequences are all 2s).

Thanks for your continued assistance,

-Jerred