plaus.val {MiscPsycho}R Documentation

IRT Plausible Values

Description

Draw random samples from the posterior density of an IRT Model

Usage

plaus.val(x, params, PV = 5, ind.dichot, M = 3, max = 5000, ...)

Arguments

x Vector of item responses
params Item parameters organized as a list of lists
PV Number of plausible values desired
ind.dichot Denotes which items in x are multiple choice
M Constant
max Maximum length of vector for storing results
... Further arguments passed to posterior

Details

Uses Rejection Sampling to generate random samples from the IRT posterior density

Value

Returns random samples from the posterior density of an IRT model

Author(s)

Harold C. Doran

Examples

# all mix
params <- list("3pl" = list(a = c(1,1), b = c(0, 1), c = c(0,0)),
               "gpcm" = list(a = c(1,1), d = list(item1 = c(0,1,2,3,4), item2 = c(0,.5,1, 1.5))))

plaus.val(x = c(0,1,2,2), params = params, ind.dichot = c(1,2))
plaus.val(x = c(0,1,2,2), params = params, ind.dichot = c(1,2), control=list(mu=2, sigma=3))

[Package MiscPsycho version 1.2 Index]