rpf (version 0.3)

rpf.info: Map an item model, item parameters, and person trait score into a information vector

Description

Map an item model, item parameters, and person trait score into a information vector

Usage

rpf.info(ii, ii.p, where, basis = 1)

Arguments

ii

an item model

ii.p

item parameters

where

the location in the latent distribution

basis

if more than 1 factor, a positive basis vector

Value

• Fisher information

References

Dodd, B. G., De Ayala, R. J. & Koch, W. R. (1995). Computerized adaptive testing with polytomous items. Applied psychological measurement 19(1), 5-22.

Examples

i1 <- rpf.drm()
i1.p <- c(.6,1,.1,.95)
theta <- seq(0,3,.05)
plot(theta, rpf.info(i1, i1.p, t(theta)), type="l")