Guttman's facet theory is described as a method for quantifying information concerning attitudes. It is stated that attitude items are not negatively correlated for usual populations. An attitude is defined as a delimited totality of behavior with respect to something and its components are elements of a set. The first step in facet research…

The Rasch model was used to equate reading comprehension tests of widely different difficulty for three groups of fifth grade students of widely different ability. Under these extreme circumstances, the Rasch model equating was unsatisfactory. (Author/CTM)

Birnbaum's three-parameter logistic item response model was used to study guessing behavior of low ability examinees on the Graduate Record Examinations (GRE) General Test, Verbal Measure. GRE scoring procedures had recently changed, from a scoring formula which corrected for guessing, to number-right scoring. The three-parameter theory was used…