ERIC Number: ED223666
Record Type: Non-Journal
Publication Date: 1982-Aug
Reference Count: N/A
Sampling Variances and Covariances of Parameter Estimates in Item Response Theory.
Lord, Frederic M.; Wingersky, Marilyn S.
A possible method is developed 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 and 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/PN)
Publication Type: Reports - Research
Education Level: N/A
Sponsor: Office of Naval Research, Arlington, VA. Personnel and Training Research Programs Office.
Authoring Institution: Educational Testing Service, Princeton, NJ.