Item selection in Polytomous CAT

In polytomous CAT, items can be selected using Fisher Information, Maximum Interval Information, or Kullback-Leibler Information. In this paper, the different item selection criteria are described. In a simulation study the criteria are compared for a number of item pools. The process of deciding which one to choose is illustrated. Application of the three item selection criteria to polytomous CAT, constrained polytomous CAT, and CAT based on multi-peaked item pools is discussed.