mlebme: Maximum likelihood and Bayes Modal estimation of ability

In lebebr01/irtoys-2: Simple interface to the estimation and plotting of IRT models

Description

Estimates the value of the latent variable ("ability") for each person by direct optimization

Usage

  mlebme(resp, ip, mu = 0, sigma = 1, method = "ML")

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.
method	"ML" for maximum likelihood or "BM" for Bayes Modal estimation. Default is "ML", in which case any values for mu and sigma will be ignored.

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 responses in column 3

Author(s)

Ivailo Partchev

See Also

eap

Examples

th.mle <- mlebme(resp=Scored, ip=Scored2pl$est)

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