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Sufficient Statistics and Latent Trait Models

Published online by Cambridge University Press:  01 January 2025

Erling B. Andersen*
Affiliation:
University of Copenhagen
*
Requests for reprints should be sent to Dr. Erling B. Andersen, Department of Statistics, University of Copenhagen, Studiestraede 6, 1455 Copenhagen, Denmark.

Abstract

For questionnaires with two answer categories, it has been proven in complete generality that if a minimal sufficient statistic exists for the individual parameter and if it is the same statistic for all values of the item parameters, then the raw score (or the number of correct answers) is the minimal sufficient statistic. It follows that the model must by of the Rasch type with logistic item characteristic curves and equal item-discriminating powers.

This paper extends these results to multiple choice questionnaires. It is shown that the minimal sufficient statistic for the individual parameter is a function of the so-called score vector. It is also shown that the so-called equidistant scoring is the only scoring of a questionnaire that allows for a real valued sufficient statistic that is independent of the item parameters, if a certain ordering property for the sufficient statistic holds.

Type
Original Paper
Copyright
Copyright © 1977 The Psychometric Society

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References

Reference Note

Birmbaum, A. On the estimation of mental ability, 1958, Randolph Air Force Base: USAF School of Aviation Medicine.Google Scholar

References

Andersen, E. B. Sufficiency and exponential families for discrete sample spaces. Journal of the American Statistical Association, 1970, 65, 12481255.CrossRefGoogle Scholar
Andersen, E. B. Conditional inference and multiple choice questionnaires. British Journal of Mathematical and Statistical Psychology, 1973, 26, 3144.CrossRefGoogle Scholar
Andersen, E. B. Conditional inference and models for measuring, 1973, Copenhagen: Mentalhygiejnisk Forlag.Google Scholar
Bahadur, B. B. Sufficiency and statistical decision functions. Annals of Mathematical Statistics, 1954, 25, 423462.CrossRefGoogle Scholar
Birnbaum, A. Test scores, sufficient statistics, and the information structures of tests. In Lord, F. M. & Novick, M. R. (Eds.), Statistical theories of mental test scores, 1968, Reading: Addison & Wesley.Google Scholar
Bock, R. D. Estimating item parameters and latent ability when responses are scored in two or more nominal categories. Psychometrika, 1972, 37, 2951.CrossRefGoogle Scholar
Denny, J. L. Sufficient statistics and discrete exponential families. Annals of Mathematical Statistics, 1973, 43, 13201322.CrossRefGoogle Scholar
Lawley, D. N. On problems connected with item selection and test construction. Proceedings of the Royal Society of Edinburgh, 1943, 61, 273287.Google Scholar
Lord, F. M. A theory of test scores. Psychometric Monograph, 1952, 19(7).Google Scholar
Rasch, G. Probabilistic models for some intelligence and attainment tests, 1960, Copenhagen: Danmarks Paedagogiske Institut.Google Scholar
Samejima, F. A general model for free-response data. Psychometric Monograph Supplement, 1972, 37(1, Pt. 2).Google Scholar