Recent developments in multilevel modeling made it possible to model the relationships between item properties and examinee properties within the multilevel and structural equation modeling framework. In this study, the performance of the multilevel two parameter logistic item response model (2PL IRM) was investigated for estimating item difficulty and discrimination parameters and equating a test among different grade levels under the presence of differential item functioning (DIF) by using real and simulation data. A statewide data, designed for vertical scaling, were used with three different adjacent grade levels. The data were collected for the Florida Comprehensive Achievement Test in 2001. In addition, simulated data comparable to large-scale assessment data from two grade levels were analyzed to control for conditions of different numbers of DIF items. The performance of 2PL IRMs with modeling of the DIF and inclusion of an examinee-level variable was compared with traditional IRT for the development of a vertical scale. It was found that 2PL IRM without any DIF parameter produced the same item difficulty and discrimination parameters. Furthermore, 2PL IRM generated the same scale score as traditional IRT. The inclusion of an examinee variable (grade level) in 2PL IRM produced a better vertical scale in comparison to 2PL IRT. The modeling of nonuniform DIF for some of the anchor items, in addition to the examinee-level variable, resulted in the same scale as the previous model; however, the modeling of uniform DIF for some of the anchor items distorted the vertical scale. A small simulation study was designed to investigate the effects of DIF items on vertical equating with respect to presence of uniform, nonuniform, and both nonuniform and uniform DIF exhibiting on some of anchor items. It was found that distortion of the scale increased as the number of nonuniform DIF items increased in the anchor set. The scale distortion got larger than the effects of having one type of DIF when items in the anchor set had both types of DIF at the same time. There was one conflicting result: Increasing the number of uniform DIF items in an anchor set decreased the scale distortion when only uniform DIF items were present. However, this could have been the result of random error due to the limited simulation size. There was one drawback of multilevel IRM in using the large-scale assessment data. The computation time needed to complete the calibration process was far beyond practicality for a comprehensive state testing program. However, multilevel IRM potentially provides more flexibility for investigating the dimensions that affect the success. Directions for future research and limitations are also discussed. / A Dissertation Submitted to the Department of Educational Psychology and Learning
Systems in Partial Fulfillment of the Requirements for the Degree of Doctor of
Philosophy. / Spring Semester, 2006. / January 20, 2006. / FCAT, Developmental Scale, Differential Item Functioning, Vertical Equating, Multilevel Item Response Model, GLLAMM / Includes bibliographical references. / Akihito Kamata, Professor Directing Dissertation; Colleen Kelley, Outside Committee Member; Richard Tate, Committee Member; Albert Oosterhof, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_175995 |
| Contributors | Turhan, Ahmet (authoraut), Kamata, Akihito (professor directing dissertation), Kelley, Colleen (outside committee member), Tate, Richard (committee member), Oosterhof, Albert (committee member), Department of Educational Psychology and Learning Systems (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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