dpv {irtoys}R Documentation

Draw plausible values

Description

Draws (by rejection sampling) plausible values from the posterior distribution of ability

Usage

dpv(resp, ip, mu=0, sigma=1, n=5)

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.
mu Mean of the apriori distribution. Ignored when method="ML". Default is 0.
sigma Standard deviation of the apriori distribution. Ignored when method="ML". Default is 1.
n The number of plausible values to draw for each person (default is 5).

Value

A matrix with n columns

Author(s)

Ivailo Partchev

See Also

mlebme, eap

Examples

data(Scored)
p.2pl <- est(Scored, model="2PL", engine="ltm")
plval <- dpv(resp=Scored, ip=p.2pl)

[Package irtoys version 0.1.2 Index]