Estimating Non-Normal Latent Trait Distributions within Item Response Theory Using True and Estimated Item Parameters
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| Title: | Estimating Non-Normal Latent Trait Distributions within Item Response Theory Using True and Estimated Item Parameters |
|---|---|
| Language: | English |
| Authors: | Sass, D. A., Schmitt, T. A., Walker, C. M. |
| Source: | Applied Measurement in Education. Jan 2008 21(1):65-88. |
| Availability: | Lawrence Erlbaum. Available from: Taylor & Francis, Ltd. 325 Chestnut Street Suite 800, Philadelphia, PA 19106. Tel: 800-354-1420; Fax: 215-625-2940; Web site: http://www.tandf.co.uk/journals/default.html |
| Peer Reviewed: | Y |
| Physical Description: | |
| Page Count: | 24 |
| Publication Date: | 2008 |
| Document Type: | Journal Articles Reports - Research |
| Descriptors: | Difficulty Level, Item Response Theory, Test Items, Computation, Error of Measurement, Test Construction |
| DOI: | 10.1080/08957340701796415 |
| ISSN: | 0895-7347 |
| Abstract: | Item response theory (IRT) procedures have been used extensively to study normal latent trait distributions and have been shown to perform well; however, less is known concerning the performance of IRT with non-normal latent trait distributions. This study investigated the degree of latent trait estimation error under normal and non-normal conditions using four latent trait estimation procedures and also evaluated whether the test composition, in terms of item difficulty level, reduces estimation error. Most importantly, both true and estimated item parameters were examined to disentangle the effects of latent trait estimation error from item parameter estimation error. Results revealed that non-normal latent trait distributions produced a considerably larger degree of latent trait estimation error than normal data. Estimated item parameters tended to have comparable precision to true item parameters, thus suggesting that increased latent trait estimation error results from latent trait estimation rather than item parameter estimation. (Contains 6 tables, 3 figures, and 1 footnote.) |
| Abstractor: | Author |
| Number of References: | 29 |
| Entry Date: | 2008 |
| Accession Number: | EJ792208 |
| Database: | ERIC |
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| Abstract: | Item response theory (IRT) procedures have been used extensively to study normal latent trait distributions and have been shown to perform well; however, less is known concerning the performance of IRT with non-normal latent trait distributions. This study investigated the degree of latent trait estimation error under normal and non-normal conditions using four latent trait estimation procedures and also evaluated whether the test composition, in terms of item difficulty level, reduces estimation error. Most importantly, both true and estimated item parameters were examined to disentangle the effects of latent trait estimation error from item parameter estimation error. Results revealed that non-normal latent trait distributions produced a considerably larger degree of latent trait estimation error than normal data. Estimated item parameters tended to have comparable precision to true item parameters, thus suggesting that increased latent trait estimation error results from latent trait estimation rather than item parameter estimation. (Contains 6 tables, 3 figures, and 1 footnote.) |
|---|---|
| ISSN: | 0895-7347 |
| DOI: | 10.1080/08957340701796415 |
