Abstract

Polytomous item response theory (IRT) models are mathematical models used to help us understand the interaction between examinees and test questions where the test questions have various response categories. These test questions are not scored in a simple dichotomous manner (i.e., correct/incorrect); rather, they are scored in way that reflects the particular score category that an examinee has achieved, been classified into, or selected (e.g., a score point of 2 on an item that is scored from 0 to 4, or selecting “somewhat agree” on a survey).