Abstract
Maximum-likelihood estimators of true score variance and error variance for mental tests are derived for six different models of equivalent measurements. Statistical properties of the estimators are examined. Main emphasis is placed upon essentiallyτ-equivalent measurements. A statistical criterion for this type of measurement is given. The solution of the comparatively simple maximum-likelihood equations is effected by means of a rapid Newton-Raphson procedure. Two different initial estimators are considered and their relative merits in terms of second moments evaluated. Four numerical examples are appended by way of illustration.
Similar content being viewed by others
References
Anderson, T. W.Introduction to multivariate statistical analysis. New York: Wiley, 1958.
Gulliksen, H.Theory of mental tests. New York: Wiley, 1950.
Jöreskog, K. G. Statistical models for congeneric test scores.Proceedings, 76th Annual Convention, APA, 1968, 213–214.
Kristof, W. Statistical inferences about the error variance.Psychometrika, 1963,28, 129–143. (a)
Kristof, W. The statistical theory of stepped-up reliability coefficients when a test has been divided into several equivalent parts.Psychometrika, 1963,28, 221–238. (b)
Lord, F. M., & Novick, M. R.Statistical theories of mental test scores. Reading, Mass.: Addison-Wesley, 1968.
Novick, M. R., & Lewis, C. Coefficient alpha and the reliability of composite measurements.Psychometrika, 1967,32, 1–13.
Wilks, S. S. Sample criteria for testing equality of means, equality of variances, and equality of covariances in a normal multivariate distribution.Annals of Mathematical Statistics, 1946,17, 257–281.
Author information
Authors and Affiliations
Additional information
Paper read at the Mathematical Psychology Meeting, August 28, 1968, at Stanford, Calfornia.
This research was supported in part by the National Institute of Child Health and Human Development, Research Grant 1 P01 HD01762.
Rights and permissions
About this article
Cite this article
Kristof, W. Estimation of true score and error variance for tests under various equivalence assumptions. Psychometrika 34, 489–507 (1969). https://doi.org/10.1007/BF02290603
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02290603