@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.}
}
@article {55,
	title = {a-stratified multistage computerized adaptive testing with b blocking},
	journal = {Applied Psychological Measurement},
	volume = {25},
	number = {4},
	year = {2001},
	pages = {333-41},
	abstract = {Proposed a refinement, based on the stratification of items developed by D. Weiss (1973), of the computerized adaptive testing item selection procedure of H. Chang and Z. Ying (1999). Simulation studies using an item bank from the Graduate Record Examination show the benefits of the new procedure. (SLD)},
	keywords = {computerized adaptive testing},
	author = {Chang, Hua-Hua and Qian, J. and Yang, Z.}
}
