calctheta {lordif}R Documentation

calculates EAP theta and associated standard error

Description

Calculates the Expected A Posteriori (EAP) theta and the associated posterior standard deviation (PSD) as standard error estimates.

Usage

calctheta(ipar, resp.data, theta, prior.mean = 0, prior.sd = 1)

Arguments

ipar a data frame containing the following columns: a, cb1, cb2,..., cb(maxCat)
resp.data a data frame containing item responses
theta a theta grid (quadrature points)
prior.mean prior mean
prior.sd prior standard deviation

Details

Calculates EAP theta estimates and PSD standard error estimates based on the input item parameters (ipar) and the item response data (resp.data).

Value

A list object with the components

EAP Expected A Posteriori estimates of theta
SE Standard Error estimates

Note

Not all item responses may be present.

Author(s)

Seung W. Choi <s-choi@northwestern.edu>

References

Bock, R. D. & Mislevy, R. J. (1982). Adaptive EAP Estimation of Ability in a Microcomputer Environment. Applied Psychological Measurement, 6(4), 431-444.

See Also

calcprob, probgrm

Examples

## Not run: calctheta(ipar,resp.data)

[Package lordif version 0.1-4 Index]