MDIFF: Compute multidimensional difficulty index

In xzhaopsy/MIRT: Multidimensional Item Response Theory

Description

Returns a matrix containing the MDIFF values (Reckase, 2009). Only suppored for items of class 'dich' and 'graded'.

Usage

MDIFF(x, which.items = NULL)

Arguments

x	an object of class 'SingleGroupClass'
which.items	a vector indicating which items to select. If NULL is used (the default) then MDISC will be computed for all items

Author(s)

Phil Chalmers [e-mail]

References

Chalmers, R., P. (2012). mirt: A Multidimensional Item Response Theory Package for the R Environment. Journal of Statistical Software, 48(6), 1-29. doi: 10.18637/jss.v048.i06

Reckase, M. D. (2009). Multidimensional Item Response Theory. Springer.

See Also

extract.group, MDISC

Examples

## Not run: 

mod <- mirt(Science, 2)
MDIFF(mod)

mod <- mirt(expand.table(LSAT7), 2)
MDIFF(mod)


## End(Not run)

xzhaopsy/MIRT documentation built on May 29, 2019, 12:42 p.m.