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…

Previous research has studied the effects of different methods of item option weighting on the reliability and concurrent and predictive validity of achievement tests. Increases in reliability are generally found, but with mixed results for validity. Several methods of producing option weights, (i.e., Guttman internal and external weights and…

The effectiveness of a model for determining a minimal cut-off score for criterion-referenced tests was examined. The model, based upon techniques presented originally by Nedelsky and by Angoff, was first used in conjunction with a multiple choice test developed for use in certifying school counselors in Georgia. A "knowledge estimation panel" was…