Item Response Theory
1 Overview
https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html
https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html
---
title: "Item Response Theory"
---
# Overview
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html>
# Analysis examples
## 1-parameter logistic model
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html#sec-irt-onePL>
## 2-parameter logistic model
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html#sec-irt-twoPL>
## 2-parameter multi-dimensional logistic model
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html#sec-irt-twoPLmultidimensional>
## 3-parameter logistic model
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html#sec-irt-threePL>
## 4-parameter logistic model
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html#sec-irt-fourPL>
## Graded response model
<https://isaactpetersen.github.io/Principles-Psychological-Assessment/item-response-theory.html#sec-irt-gradedResponseModel>