@article {56, title = {a-Stratified multistage computerized adaptive testing with b blocking}, journal = {Applied Psychological Measurement}, volume = {25}, number = {4}, year = {2001}, pages = {333-341}, abstract = {Chang \& Ying{\textquoteright}s (1999) computerized adaptive testing item-selection procedure stratifies the item bank according to a parameter values and requires b parameter values to be evenly distributed across all strata. Thus, a and b parameter values must be incorporated into how strata are formed. A refinement is proposed, based on Weiss{\textquoteright} (1973) stratification of items according to b values. Simulation studies using a retired item bank of a Graduate Record Examination test indicate that the new approach improved control of item exposure rates and reduced mean squared errors. }, isbn = {0146-6216}, author = {Chang, Hua-Hua and Qian, J. and Ying, Z.} }