Publications & Resources

Does Adaptive Testing Violate Local Independence?

Apr 1998

Robert J. Mislevy and Hua-Hua Chang

Item response theory posits “local independence,” or conditional independence of item responses given item parameters and examinee proficiency parameters. The usual definition of local independence, however, addresses the context of fixed tests and appears to yield incorrect response-pattern probabilities in the context of adaptive testing. The paradox is resolved by introducing additional notation to deal with the item selection mechanism. Implications for estimation of examinee proficiency are noted.

Mislevy, R. J., & Chang, H.-H. (1998). Does adaptive testing violate local independence? (CSE Report 476). Los Angeles: University of California, Los Angeles, National Center for Research on Evaluation, Standards, and Student Testing (CRESST).