[Rasch] Rasch S.E at the cut score...reciprocal?

Imogene Rothnie imogene.rothnie at sydney.edu.au
Fri Nov 1 09:23:06 EST 2013

I have recently read some Rasch digests about error at the cut point of the test. These suggest that to convert the Rasch logit S.E. at the cut point of the test to raw score units (or approximately)  one should take the reciprocal of the S.E. of the nominated logit value.
HOWEVER, as the S.E. gets smaller (good) the reciprocal gets bigger! And so the raw score range within the boderzone becomes larger. I must be missing something?
E.g we have a test with very small S.E. at cut logit measure of 0.05...  1/0.05 is 20- a borderzone of 40marks...whereas an S.E. of 0.15, hence 1/0.15  would give you a raw score range of 14...


IMOGENE ROTHNIE | Lecturer (Assessment)
Office of Medical Education | Faculty of Medicine
Rm 108, Edward Ford Bdg  A27 | The University of Sydney | NSW | 2006
T +61 2 9036 6434  | F +61 2 9036 7580   | M +61 418 381 359
E imogene.rothnie at sydney.edu.au<mailto:imogene.rothnie at sydney.edu.au>  | W http://ome.med.usyd.edu.au<http://sydney.edu.au>
This email plus any attachments to it are confidential. Any unauthorised use is strictly prohibited. If you receive this email in error, please delete it and any attachments.
Please think of our environment and only print this e-mail if necessary.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailinglist.acer.edu.au/pipermail/rasch/attachments/20131031/6c9d2317/attachment-0001.html 

More information about the Rasch mailing list