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The Use Of Item Response Theory In Developing A Phonics Diagnostic Inventory, Cynthia A. Pirani-Mcgurl

Open Access Dissertations

This study was conducted to investigate the reliability of the Phonics Diagnostic Inventory (PDI), a curriculum-based, specific skill mastery measurement tool for diagnosing and informing the treatment of decoding weaknesses. First, a modified one-parameter item response theory model was employed to identify the properties of potential items for inclusion in each subtest to then inform the construction of subtests using the most reliable items. Second, the properties of each subtest were estimated and examined. The test information and test characteristic curves (TCC) for the newly developed forms are reported. Finally, the accuracy and sensitivity of PDI cut scores for each …