@geekie/irt

IRT tools in JavaScript

About

This library contains JavaScript implementations of functions related to Item Response Theory logistic models.

Usage

• itemResponseFunction(zeta: Zeta, theta: number)

Calculates the probability that a person with the given ability level theta will answer correctly an item.

zeta is an object with the 3 parameters: {a, b, c}

• information(zeta: Zeta, theta: number) | information(zetaArray: Array<Zeta>, theta: number)

Calculates how much information an item (or an array of items) contributes for a given ability level theta.

• estimateAbilityEAP(answers: Array<0 | 1>, zetaArray: Array<Zeta>)

Estimate a person's ability using the EAP method (reference).

answers is an array of 0 or 1 representing if the answer given is correct, related to the items of zetaArray. 1 means the answers is correct.

Example: answers[0] represents if the person answered the item related to zetaArray[0].