Dear Stata users
I am evaluating a polytomous IRT model in Stata using GLLAMM and
frequently encounter the following errors. Can someone help?
1. Often I get a msg that says, flat or discontinuous region
encountered. What can I do to fix this?
2. Sometimes, the log likelihood produces identical estimates as the
previos estimate and still continues to run. Does this mean that it
has gotten into an unconditional looping or does it mean that there is
some problem with the data?
3. Thirdly, when I estimate the thresholds for the items, should these
estimates be rescaled?
I would really appreciate any advice.
Thanks
Prathiba
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