personfit calculates the Zh values from Drasgow,
Levine and Williams (1985) for unidimensional and
multidimensional models, as well as infit and outfit
statistics. The returned object is a data.frame
consisting either of the tabulated data or full data with
the statistics appended to the last columns.
Usage
personfit(x, degrees = NULL)
Arguments
x
a computed model object of class
ExploratoryClass, ConfirmatoryClass, or
MultipleGroupClass
degrees
the degrees angle to be passed to the
iteminfo function
References
Drasgow, F., Levine, M. V., & Williams, E. A. (1985).
Appropriateness measurement with polychotomous item
response models and standardized indices. Journal
of Mathematical and Statistical Psychology, 38, 67-86.
Reise, S. P. (1990). A comparison of item- and person-fit
methods of assessing model-data fit in IRT. Applied
Psychological Measurement, 14, 127-137.
#make some dataset.seed(1234)
a <- matrix(rnorm(20),ncol=1)
d <- matrix(rnorm(20),ncol=1)
items <- rep('dich', 20)
data <- simdata(a,d, 2000, items)
x <- mirt(data, 1)
fit <- personfit(x)
head(fit)