lordif (version 0.1-2)

calctheta: 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

Value

• A list object with the components
• EAP
  Expected A Posteriori estimates of theta
• SE
  Standard Error estimates

Details

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

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

calctheta(ipar,resp.data)