TY - CONF T1 - Data sparseness and online pretest calibration/scaling methods in CAT T2 - Paper presented at the annual meeting of the American Educational Research Association Y1 - 2001 A1 - Ban, J A1 - Hanson, B. A. A1 - Yi, Q. A1 - Harris, D. JF - Paper presented at the annual meeting of the American Educational Research Association CY - Seattle N1 - Also ACT Research Report 2002-1) ER -