, Volume 37, Issue 1, pp 29–51 | Cite as

Estimating item parameters and latent ability when responses are scored in two or more nominal categories

  • R. Darrell Bock


A multivariate logistic latent trait model for items scored in two or more nominal categories is proposed. Statistical methods based on the model provide 1) estimation of two item parameters for each response alternative of each multiple choice item and 2) recovery of information from “wrong” responses when estimating latent ability. An application to a large sample of data for twenty vocabulary items shows excellent fit of the model according to a chi-square criterion. Item and test information curves are compared for estimation of ability assuming multiple category and dichotomous scoring of these items. Multiple scoring proves substantially more precise for subjects of less than median ability, and about equally precise for subjects above the median.


Public Policy Statistical Theory Multiple Choice Response Alternative Latent Trait 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Psychometric Society 1972

Authors and Affiliations

  • R. Darrell Bock
    • 1
  1. 1.University of ChicagoUSA

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