[Rasch] Separability of parameters

Snider-Lotz, Tom tsnider-lotz at previsor.com
Thu Sep 28 02:39:01 EST 2006

Hello everybody -

I recently read a manuscript that said the Rasch model was the only one
that featured separability of parameters.  One inference I make from
that statement is that, for 2PL and 3PL models, the IRT item parameters
are somewhat dependent of the sample on which they are developed.  Is
that correct, or do I misunderstand this (as I often do).

Thanks, all.

 -- Tom Snider-Lotz

Thomas G. Snider-Lotz, Ph.D.
Principal Scientist
1805 Old Alabama Road, Suite 150
Roswell, GA 30076
T:678.832.0555 F:770.642.6115
tsnider-lotz at previsor.com
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