Reference:

1
Reference

• Wang, Bradlow and Wainer (2002) A General
  Bayesian Model for Testlets Theory and
  Applications. GRE Board Professional Report No.
  98-01P ETS Research Report 02-02
• Wainer and Wang (2001),Using a New Statistical
  Model for Testlets to Score TOEFL. ETS technical
  report, TR-16
• Wainer, Bradlow, Du (2000) Testlet Response
  theory An analog for the 3PL Model Useful in
  Testlet-Based Adaptive Testing. Computerized
  adaptive Testing, theory practice, ch13
• Wainer (2000) Computerized Adaptive Testing, 2nd
  edition, P245-253