Description Usage Arguments Details Value Author(s) References See Also Examples
This function estimates the person drift rate and person boundary separation for diffIRT
objects.
1 |
object |
A |
start |
If |
se |
Logical; Denoting whether standard errors of the parameters should be estimated (can be time consuming, therefore, default is |
control |
a list of control values for the optimisation |
The optimisation method used by optim
. Default "BFGS".
See optim
for details and default.
See optim
for details and default.
See optim
for details and default.
See optim
for details and default.
See optim
for details and default.
See optim
for details. Default is 1999.
See optim
for details and default.
factest
returns empirical Bayes estimates of the person drift rate and
the person boundary separation. See diffIRT for more explanation concerning the parameters in the
D-diffusion and Q-diffusion IRT model.
Function factest
returns a matrix of parameter estimates and - if se
=T - standard errors.
Dylan Molenaar d.molenaar@uva.nl
Navarro, D.J. & Fuss, I.G. (2009). Fast and accurate calculations for first-passagetimes in Wiener diffusion models. Journal of mathematical psychology, 53, 222-230.
Tuerlinckx, F., & De Boeck, P. (2005). Two interpretations of the discrimination parameter. Psychometrika, 70, 629-650.
van der Maas, H.L.J., Molenaar, D., Maris, G., Kievit, R.A., & Borsboom, D. (2011). Cognitive Psychology Meets Psychometric Theory: On the Relation Between Process Models for Decision Making and Latent Variable Models for Individual Differences. Psychological Review, 118, 339-356.
diffIRT
for fitting diffusion IRT models.
simdiff
for simulating data according to the D-diffusion or Q-diffusion IRT model.
QQdiff
and RespFit for model fit assesment.
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