Concept inventories hold tremendous promise for promoting the rigorous evaluation of teaching methods that might remedy common student misconceptions and promote deep learning. The measurements from concept inventories can be trusted only if the concept inventories are evaluated both by expert feedback and statistical scrutiny (psychometric…

Nedelsky (1954) has suggested a procedure for determining the minimum passing score on a multiple-choice test. In this procedure expert judges estimate the probable score of a minimally competent examinee. The technique does not refer to the students' performance data. The purposes of this paper are: (1) to introduce a modification to the Nedelsky…