Early work on CAT tended to use existing sets of items which came from fixed length test forms. These sets of items were selected to meet much different requirements than are needed for a CAT; decision making or covering a content domain. However, there was also some early work that suggested having items equally distributed over the range of proficiency that was of interest or concentrated at a decision point. There was also some work that showed that there was bias in proficiency estimates when an item pool was too easy or too hard. These early findings eventually led to work on item pool design and, more recently, on item pool evaluation. This presentation gives a brief overview of these topics to give some context for the following presentations in this symposium.

Session Video