[IPAC-List] scoring multiple answer questions

[Megan Paul]

I am reviewing an on-the-job knowledge test developed by a client for 
in-house use (a pseudo certification test, I guess you could say). Many 
of the items are multiple answer, with the number of right and wrong 
answers varying across items. They want to give partial credit for 
getting some of the right answers correct. To do that, they'll also need 
to penalize for selecting wrong answers (otherwise a test taker need 
only select all answers--right or wrong--to get full credit). So...I'm 
trying to help them figure out a reasonable way to do this. If the wrong 
answers are worth the same points as the right answers (albeit with a 
negative value), there are cases where a test taker could lose more 
points than they'd earn. The only practice I can think to apply is the 
correction for guessing, but I've never used such formulas, and it seems 
like it won't be so straightforward, given that a) we're talking about 
the possibility of multiple wrong answers for each question and b) the 
number of right and wrong answers varies across items (i.e., I can't 
arrive at a single formula for the whole test; might have to be a 
formula for each item? Is there such a thing?).

Any thoughts?

To be clear, I did not develop this test. I'm just being asked to weigh 
in after the fact.

Thanks in advance,
Megan

-- 
Megan E. Paul, Ph.D.
Research Assistant Professor
University of Nebraska-Lincoln
Center on Children, Families, and the Law
206 S. 13th Street, Suite 1000
Lincoln, NE 68588-0227

(402) 472-9812 Office
(402) 472-8412 Fax