| MDIFF {mirt} | R Documentation |
Returns a matrix containing the MDIFF values (Reckase, 2009). Only suppored for items of class 'dich' and 'graded'. Note that the logistic intercept parameters are divided by 1.702 to match the normal ogive metric.
MDIFF(x, which.items = NULL)
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 |
Phil Chalmers rphilip.chalmers@gmail.com
Reckase, M. D. (2009). Multidimensional Item Response Theory. Springer.
## Not run: mod <- mirt(Science, 2) MDIFF(mod) ## End(Not run)