api: The Z3 appropriateness index

Description Usage Arguments Value Author(s) References Examples

View source: R/itemfit.R

Description

Computes the Z3 appropriateness index, a measure of person fit in IRT models

Usage

1
  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: a matrix with one row per item, and three columns: [,1] item discrimination a, [,2] item difficulty b, and [,3] asymptote c.

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

1

lebebr01/irtoys-2 documentation built on May 20, 2019, 11:29 p.m.