Item-response theory (IRT)assumes that the model fits the data. One commonly overlooked aspect of model-fit assessment is an examination of personfit, or person-fit assessment (PFA). One reason that PFA lacks popularity among psychometricians is that comprehensive software is notpresent.This dissertation outlines the development and testing ofa new software package, called wizirt, that will begin to meet this need. This software package provides a wide gamut of tools to the user but is currently limited to unidimensional, dichotomous, and parametricmodels. The wizirt package is built in the open source language R, where it combines the capabilities of a number of other R packages under a single syntax.In addition to the wizirt package, I have created a number of resources to help users learn to use the package. This includes support for individuals who have never used R before, as well as more experienced R users.
College and Department
Educational Inquiry, Measurement, and Evaluation
BYU ScholarsArchive Citation
Pfleger, Phillip Isaac, "Designing Software to Unify Person-Fit Assessment" (2020). Theses and Dissertations. 8776.
item response theory, computer software, test validity, statistical analysis