An alternative definition has been developed of the delta scale of item difficulty used at Educational Testing Service. The traditional delta scale uses an inverse normal transformation based on normal ogive models developed years ago. However, no use is made of this fact in typical uses of item deltas. It is simply one way to make the probability…

Specific questions addressed in this study include how time limits affect a test's construct and predictive validities, how time limits affect an examinee's time allocation and test performance, and whether the assumption about how examinees answer items is valid. Interactions involving an examinee's sex and age are studied. Two parallel forms of…