ABSTRACT
One important lesson learned from the controversy several years ago between the Educational Testing Service (ETS) and Stanley H. Kaplan Educational Centers Ltd. about the computerbased version of the Graduate Record Examination (GRE) was that larger item banks than had been initially assumed necessary are needed to support flexibly scheduled computer-based tests. Large item banks are needed to keep conditional item exposure levels low to protect the validity of test scores (Davey & Nering, 2002). Of course, one consequence is the increased cost to produce the extra test items, and another is the increased cost to field test substantially more test items.
