mpt2irt-package: mpt2irt: Bringing Multinomial Processing Tree Models To Item...

Description Details Author(s) References Examples

Description

Multinomial processing tree (MPT) models are used to differentiate between different cognitive processes in categorical data. Those can be lifted to hierarchical MPT models to account for person- and/or item effects (Matzke et al., 2015): This is done by reparameterizing each MPT parameter by means of an item response (IRT) model. Boeckenholt (2012) developed a model to disentengle two reponse styles, namely midpoint (MRS) and extreme responding (ERS), and the target trait. This package allows to fit an extension of this Boeckenholt Model to acquiescence (ARS). It makes use of Bayesian hierarchical models requiring JAGS or Stan.

Details

The package requires installation of JAGS (http://mcmc-jags.sourceforge.net) and/or Stan (http://mc-stan.org) to sample from the posterior.

Author(s)

Hansjoerg Plieninger & Daniel W. Heck

References

Plieninger, H., & Heck, D. W. (in press). A new model for acquiescence at the interface of psychometrics and cognitive psychology. Multivariate Behavioral Research. doi:10.1080/00273171.2018.1469966

Examples

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## Not run: 
N <- 20
J <- 10
betas <- cbind(rnorm(J, .5), rnorm(J, .5), rnorm(J, 1.5), rnorm(J, 0))
dat <- generate_irtree_ext(N = N, J = J, betas = betas, beta_ARS_extreme = .5)

# fit model
res1 <- fit_irtree(dat$X, revItem = dat$revItem, M = 200)
res2 <- summarize_irtree_fit(res1)
res3 <- tidyup_irtree_fit(res2, N = N, J = J, revItem = dat$revItem,
                          traitItem = dat$traitItem, fitModel = res$fitModel)
res3$plot

## End(Not run)

hplieninger/mpt2irt documentation built on Aug. 4, 2018, 10:52 a.m.