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Re: st: RE: Flat or discontinuous region encountered! Help


From   "Prathiba Natesan" <[email protected]>
To   [email protected]
Subject   Re: st: RE: Flat or discontinuous region encountered! Help
Date   Wed, 23 Aug 2006 12:02:10 -0500

Thank you for the suggestions Nick.
   Could you please tell me how I can change my data in such a case?
Is there a way I can look for anamolies/problems? I am running a 2-PL
MLIRT model on 2 datasets, a simulated dataset and a real data (with a
sample size of abt 19,000). Both of them seem to give me the same
problems.
  Also, on #2, even if I let the program run for abt a day or 2, the
program produces about 100-200 iterations of the estimates which look
identical. Sometimes the estimates are identical upto the 3rd or 4th
decimal place. Do you think I should still wait longer for it to
converge?
On a similar note, when the iterations fail to converge, what can be
done? What does it say abt the data?
I am currently working on my dissertation and these questions are
driving me crazy. I would appreciate any suggestions you might have.
Thanks
Prathiba

On 8/23/06, Prathiba Natesan <[email protected]> wrote:
Thank you for the suggestions Nick.
     Could you please tell me how I can change my data in such a case?
Is there a way I can look for anamolies/problems? I am running a 2-PL
MLIRT model on 2 datasets, a simulated dataset and a real data (with a
sample size of abt 19,000). Both of them seem to give me the same
problems.
    Also, on #2, even if I let the program run for abt a day or 2, the
program produces about 100-200 iterations of the estimates which look
identical. Sometimes the estimates are identical upto the 3rd or 4th
decimal place. Do you think I should still wait longer for it to
converge?
  On a similar note, when the iterations fail to converge, what can be
done? What does it say abt the data?
I am currently working on my dissertation and these questions are
driving me crazy. I would appreciate any suggestions you might have.
Thanks
Prathiba

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