3 research outputs found
A priori reliability of tests with cut score
The theoretical probability of misclassification in a mastery test is exactly computed using the raw
score probability distribution (in the Rasch model) as a function of the examinee???s latent ability. The
resulting misclassification probability curve, together with the latent ability distribution in the group of
examinees, completely determines the expected rate of classification errors. It is shown that several distinct
ability thresholds, playing different roles in connection to classification reliability, can be associated
to a test with a single cut score. In particular, it is possible to define (and compute) two relevant ability
intervals, which encapsulate the functioning of a mastery test (about and far from the cut score, respectively);
the dependence of these intervals on the item difficulty spectrum is investigated. Extension to the
2PL model is also discussed, with emphasis on the effects of weighted scoring
A PRIORI RELIABILITY OF TESTS WITH CUT SCORE
The theoretical probability of misclassification in a mastery test is exactly computed using the raw
score probability distribution (in the Rasch model) as a function of the examinee???s latent ability. The
resulting misclassification probability curve, together with the latent ability distribution in the group of
examinees, completely determines the expected rate of classification errors. It is shown that several distinct
ability thresholds, playing different roles in connection to classification reliability, can be associated
to a test with a single cut score. In particular, it is possible to define (and compute) two relevant ability
intervals, which encapsulate the functioning of a mastery test (about and far from the cut score, respectively);
the dependence of these intervals on the item difficulty spectrum is investigated. Extension to the
2PL model is also discussed, with emphasis on the effects of weighted scoring