A rationale for the development of cut-off scores.

Referring to an all-or-none conception of mastery, a response model is developed for items of an ordered item domain. The model defines three parameters: The probalities that masters and non-masters with respect to a particular item respond correctly to that item and the probability that an individual is a master of that item. Estimation procedures are given and a rationale for setting a cut-off score is developed. The rationale is illustrated by analysing a driver knowledge test and by determining a cut-off score.