jml {MiscPsycho}R Documentation

Joint Maximum Likelihood

Description

Estimates the Rasch model using joint maximum likelihood (JML)

Usage

jml(dat, con = 0.001, bias = FALSE)

Arguments

dat A data frame or matrix containing item responses
con Convergence criterion
bias Correction for JML bias

Details

JML estimation only has good asymptotic properties. Marginal Maximum Likelihood (MML) is a better technology for parameter estimation. However, this option is provided for users of Winsteps who may want to explore their data in R prior to working in Winsteps. JML is known to return biased parameter estimates. If bias = TRUE, then a correction for bias is made using (L-1)/L * b where L is the total number of test items and b is the original item parameter

Value

jml returns item parameter estimates, their asymptotic standard errors, the sample size per item, and the Infit and Outfit statistics found in Winsteps.

Author(s)

Harold C. Doran

References

Best Test Design. Wright and Stone (1979)

See Also

ltm


[Package MiscPsycho version 1.4 Index]