pcIRT (version 0.1)

person_par: Estimation of person parameters

Description

This function performs the estimation of person parameters for the multidimensional polytomous Rasch model or the continuous Rating Scale model.

Usage

person_par(object, ...)
## S3 method for class 'MPRM':
person_par(object, \dots, set0=FALSE)
## S3 method for class 'CRSM':
person_par(object, \dots)

Arguments

object

Object of class MPRM or CRSM

set0

if set0=TRUE for those raw scores patterns with 0 observations (except in the reference category) the person parameter value is set minimal. With this procedure it is possible to estimate at least the remaining person parameters of these raw

...

...

Value

• ptable
  table showing for each (observed) raw score the corresponding estimated person parameter and standard error
• pparList
  for each person raw score, estimated person parameter and the standard error is displayed
• fun_calls
  number of function calls
• call
  function call

Details

The estimation is performed by Maximum Likelihood Estimation. Thus, parameters for extreme scores are not calculated!

References

Fischer, G. H. (1974). Einfuehrung in die Theorie psychologischer Tests [Introduction to test theory]. Bern: Huber.

Mueller, H. (1999). Probabilistische Testmodelle fuer diskrete und kontinuierliche Ratingskalen. [Probabilistic models for discrete and continuous rating scales]. Bern: Huber.

See Also

CRSM

Examples

#estimate CRSM for the first four items
data(example1)
ex_cr <- CRSM(example1[,1:4], min=0, max=1)

#estimate person parameters for CRSM
pp <- person_par(ex_cr)