25% correct...translates to a p value of .25....which does indicate a difficult question....but a possibly reasonable

P values typically should range from .75 to .25

When you see a low p value (hard question)...you should look at the discrimination index to ensure that the question is working right (i.e. positive discriminating between students who did well on test (prepared well) and students that didn't)

If the question is hard and discriminating well..its fine

Jim

Jim Sibley

Sorry for brief message -sent from my iPad

On 2014-04-01, at 3:57 PM, Susan Hazel <[log in to unmask]> wrote:

Hi All,

Yesterday I ran a TBL and for the first time one of my teams when writing the appeal justified it by saying that only 25% of students got that question right, so it must have been ambiguous. I use the Scantron in class so that students can see for each question how they went, and this team has used the information accordingly. I won’t grant this appeal as I think they have to justify why a question was ambiguous, or why the answer was wrong, but wondered if others have had similar experience and how they handled it?

Susan

 

Susan Hazel BVSc BSc(Vet) PhD GradCert (Public Health) MANZCVSc

Senior Lecturer in Animal Behaviour, Welfare and Ethics

School of Animal & Veterinary Sciences

THE UNIVERSITY OF ADELAIDE

Roseworthy SA 5371 Australia

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