A-stratified multistage computerized adaptive testing with b blocking

Hua Hua Chang, Jiahe Qian, Zhiliang Ying

Research output: Contribution to journalArticlepeer-review


Chang & Ying'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' (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. Index terms: adaptive testing, a stratification, b blocking, item exposure rate, item selection, test security.

Original languageEnglish (US)
Pages (from-to)333-341
Number of pages9
JournalApplied Psychological Measurement
Issue number4
StatePublished - Dec 2001
Externally publishedYes

ASJC Scopus subject areas

  • Social Sciences (miscellaneous)
  • Psychology (miscellaneous)


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