api {irtoys}

The api appropriateness index

Description

Computes the api appropriateness index, a measure of person fit in IRT models

Usage

api(resp, ip, theta)

Arguments

resp

A matrix of responses: persons as rows, items as columns, entries are either 0 or 1, no missing data

ip

Item parameters: the object returned by est, or its first part.

theta

A measure of ability, typically produced with mlebme, wle etc. If missing, ML estimates will be computed automatically.

Value

A vector of length equal to the number of rows in resp, containing the appropriateness indices

Author(s)

Ivailo Partchev

References

Drasgow, F., Levine, M. V., & Williams, E. A. (1985). Appropriateness measurement with polychotomous item response models and standardized indices. British Journal of Mathematical and Statistical Psychology, 38, 67–80

Examples

api(Scored, Scored2pl)