irtoys (version 0.1.4)

eap: EAP estimation of ability

Description

Estimates the expectation of the posterior distribution of the latent variable ("ability") for each person.

Usage

eap(resp, ip, qu)

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 $c$.

qu

A quadrature object produced with normal.qu or read in with read.qu.icl

Value

• A matrix with the ability estimates in column 1, and their standard errors of measurement (SEM) in column 2, and the number of non-missing reponses in column 3

See Also

mlebme, normal.qu, read.qu.icl

Examples

data(Scored)
p.2pl <- est(Scored, model="2PL", engine="ltm")
th.eap <- eap(resp=Scored, ip=p.2pl, qu=normal.qu())