Vignettes

These vignettes show how to work with IRW data for common psychometric tasks.

R

Each of these vignettes uses the irw R package to fetch data and walks through a complete analysis.

R

Calculating IMV Values

How much does a 2PL improve on a 1PL for a given dataset?

irw mirt imv

R

Simulating Item Difficulties

How can I simulate item difficulties that reflect real-world distributions rather than idealized assumptions?

irw

R

2PL Parameters Across Datasets

What do discrimination parameters look like across many cognitive/educational datasets in the wild?

irw mirt ggplot2

R

Conducting CFA with IRW Data

How do I fit a multi-factor CFA model to an IRW personality dataset?

irw lavaan psych

R

Item Text and Difficulty

Can simple linguistic features of item wording predict proportion correct across cognitive datasets?

irw ggplot2

Python

These vignettes use the irw Python package to fetch data.

Python

IRT Models in Python

How do I fetch IRW data in Python and fit 1PL, 2PL, 3PL, and graded response models?

irw mirt girth