rrsm: Simulate Data under a Rating Scale Model

In psychotools: Psychometric Modeling Infrastructure

Simulate Data under a Rating Scale Model

Description

rrsm simulates IRT data under a rating scale model.

Usage

rrsm(theta, beta, tau, nullcats = FALSE, return_setting = TRUE)

Arguments

theta	numeric vector of person parameters. Can also be a list, then a list of length length(theta) is returned, containing multiple simulated data sets.
beta	numeric vector of item difficulty parameters.
tau	numeric vector of threshold parameters.
nullcats	logical. Should null categories be allowed?
return_setting	logical. Should a list containing slots of "beta", "tau", and "theta", as well as the simulated data matrix "data" be returned (default) or only the simulated data matrix?

Value

rrsm returns either a list of the following components:

beta	numeric vector of item difficulty parameters used,
tau	numeric vector of threshold parameters used,
theta	numeric vector (or list) of person parameters used,
data	numeric matrix containing the simulated data,

or (if return_setting = FALSE) only the numeric matrix containing the simulated data.

See Also

rpcm, rgpcm, rrm, rpl

Examples

set.seed(1)
## item responses under a rating scale model (RSM) with
## 6 persons with three different person parameters
## 9 increasingly difficult items
## 3 different threshold parameters
ppar <- rep(-1:1, each = 2)
ipar <- seq(-2, 2, by = 0.5)
tpar <- 0:2
sim <- rrsm(theta = ppar, beta = ipar, tau = tpar)

## simulated item response data along with setting parameters
sim

## print and plot corresponding item response object
iresp <- itemresp(sim$data)
iresp
plot(iresp)

psychotools documentation built on May 29, 2024, 8:12 a.m.