[Rasch] Rasch person reliability and coefficient alpha
Mike Linacre (RMT)
rmt at rasch.org
Sat May 31 08:02:38 EST 2008
They are reporting Cronbach Alpha. They probably have many extreme scores
on their 4 items. This would produce very high reliability
(reproducibility) for raw scores, but very low reliability
(reproducibility) for Rasch measures.
In physical measurement terms, we are very sure the basketball-players are
taller than the tape measure (Alpha), but we are very unsure what their
heights actually are (Rasch).
At 5/30/2008, you wrote:
>they say the items have an alpha of .84. Yet when I Rasch analyze them, I
>get a reliability of 0.00.
Editor, Rasch Measurement Transactions
rmt at rasch.org www.rasch.org/rmt/ Latest RMT: 21:4 Spring 2008
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Rasch