The use of item response theory in developing the Dynamic Indicators of Vocabulary Skills parallel forms
The primary purpose of this study was to develop ten parallel-forms of the DIVS measures using a modified one-parameter model of item response theory (IRT). Secondarily, the IRT created forms were compared to the original forms. Data were collected on pre-kindergarten and kindergarten students. The item responses first underwent preliminary analyses and poor and negatively discriminating items were removed. Then, the item characteristics were estimated and parallel-forms were created. The test information and test characteristic curves (TCC) for the newly developed forms are reported. The preexisting DIVS forms, which had been originally created by random assignment, were compared to the new IRT created forms. Overall, the IRT forms yielded vastly improved test characteristics. Implications for future studies are discussed.
0525: Educational psychology