Accession Number : ADA119609

Title :   Sampling Variances and Covariances of Parameter Estimates in Item Response Theory.

Descriptive Note : Technical rept.,

Corporate Author : EDUCATIONAL TESTING SERVICE PRINCETON NJ

Personal Author(s) : Lord,Frederic M ; Wingersky,Marilyn S

PDF Url : ADA119609

Report Date : Aug 1982

Pagination or Media Count : 50

Abstract : This paper develops a possible method for computing the asymptotic sampling variance-covariance matrix of joint maximum likelihood estimates in item response theory when both item parameters and abilities are unknown. For a set of artificial data, results are compared with empirical values; also with the variance-covariance matrices found by the usual formulas for the case where the abilities are known, or where the item parameters are known. The results are consistent with the conjecture that the new method is asymptotically correct except for errors due to grouping. (Author)

Descriptors :   *Maximum likelihood estimation, *Parametric analysis, *Analysis of variance, *Covariance, Sampling, Response, Computations, Comparison, Methodology, Asymptotic normality, Matrix theory, Errors

Subject Categories : Statistics and Probability

Distribution Statement : APPROVED FOR PUBLIC RELEASE