Examining MIRT Models from a Graphical Perspective using RShiny and Mathematica

Session Type: Training Session

Abstract

The purpose of this workshop is to walk researchers through 15 different item and test analyses based upon two-dimensional IRT compensatory model item parameters estimated from assessment data. We will illustrate each analysis graphically using the software RShiny and Mathematica. Two software packages were developed for this Workshop: MIRTGraphRS and MIRTGraphM. The packages consist of a suite of RShiny and Mathematica programs that require the user to input a file containing their estimated two-dimensional compensatory item parameters and then the user can select to run one of 15 different graphics programs. All graphics can be downloaded to include in reports or articles. The MIRTGraphRS and MIRTGraphM packages are divided into five categories of graphics for Total Test, Test Information, Two-Dimensional Ability Estimation, and Differential Item Functioning. The goal of this workshop is to provide graphical tools that will yield greater insight into what tests are measuring and inform future test development.

The session will have an interactive format where the audience can use their laptops and follow the presenters as they describe the various graphics. Attendees will receive a manual, detailing each of the graphics, and a copy of all the R Shiny and Mathematica programs that are discussed.

Sub Unit

• Training Sessions

Session Organizer

• Terry Ackerman, U of Iowa

Presenters

• Mingqin Zhang, National Council of State Boards of Nursing (NCSBN)

• Qing Xie, University of Iowa