simCRSM: simulate data according to CRSM

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/simCRSM.R

Description

With this function data sets according to the Continous Rating Scale Model are simulated

Usage

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simCRSM(itempar, disp, perspar, mid = 0.5, len = 1, seed = NULL)

Arguments

itempar

a numerical vector with item parameters

disp

a number setting the dispersion parameter for the item set

perspar

a numerical vector with the person parameters

mid

the midpoint of the response scale (on which the data set is generated)

len

the length of the response scale (on which the data set is generated)

seed

a seed for the random number generated can optionally be set

Details

The midpoint and the length of the response scale define the interval of the data set generated. The default of the function generates data according to a response scale between 0 and 1 - that is midpoint 0.5 and length 1.

Value

datmat

simulated data set

true_itempar

the fixed item parameters according to the input

true_disppar

the fixed dispersion parameter according to the input

true_perspar

the fixed person parameters according to the input

Author(s)

Christine Hohensinn

References

Mueller, H. (1987). A Rasch model for continuous ratings. Psychometrika, 52, 165-181.

See Also

simMPRM

Examples

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#set item parameters
item_p <- c(-1.5,-0.5,0.5,1)

#set dispersion parameter for items
dis_p <- 5

#generate person parameters by a standard normal dispersion
pp <- rnorm(50, 0,1)

#simulate data set
#this is only an illustrating example for simulating data!
#In practice, a sample size of n=50 will be too small for most application
#demands
simdatC <- simCRSM(item_p, dis_p, pp)

pcIRT documentation built on May 1, 2019, 11:09 p.m.