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ERIC Number: ED339738
Record Type: Non-Journal
Publication Date: 1991-Aug
Pages: 38
Abstractor: N/A
Reference Count: N/A
Empirical Estimation of Standard Errors of Compensatory MIRT Model Parameters Obtained from the NOHARM Estimation Program. ACT Research Report Series.
Miller, Timothy R.
Two studies were carried out to evaluate the quality of multidimensional item response theory (MIRT) model parameter estimates obtained from the computer program NOHARM. The purpose of the first study was to compute empirical estimates of the standard errors of the parameters. In addition, the parameter estimates were evaluated for bias and the effects of using different starting values and anchor items. Real data from a 1987 national administration of a form of the Preliminary American College Test (P-ACT) mathematics test with a sample of 30,000 cases and 10 replication samples of 2,000 students each. The second study was included to compare the performance of NOHARM with the findings of an earlier simulation study that evaluated other MIRT estimation programs. The results are generally good, with fairly small standard errors for most parameter estimates and little indication of bias. Although the estimation procedure appeared to be robust under different starting values, the specific choice of items used to anchor the solution appears to have important effects on the magnitude of the estimated standard errors. The comparison of NOHARM with other programs was very favorable and supports the use of NOHARM for practical MIRT applications. Eight references are listed, and 10 tables present study data. (SLD)
ACT Research Report Series, P.O. Box 168, Iowa City, IA 52243.
Publication Type: Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: Office of Naval Research, Arlington, VA. Cognitive and Neural Sciences Div.
Authoring Institution: American Coll. Testing Program, Iowa City, IA.