expected.test {mirt} | R Documentation |
Given an estimated model compute the expected test score. Returns the expected values in the same form as the data used to estimate the model.
expected.test( x, Theta, group = NULL, mins = TRUE, individual = FALSE, which.items = NULL )
x |
an estimated mirt object |
Theta |
a matrix of latent trait values |
group |
a number signifying which group the item should be extracted from (applies to 'MultipleGroupClass' objects only) |
mins |
logical; include the minimum value constants in the dataset. If FALSE, the expected values for each item are determined from the scoring 0:(ncat-1) |
individual |
logical; return tracelines for individual items? |
which.items |
an integer vector indicating which items to include in the expected test score. Default uses all possible items |
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
## Not run: dat <- expand.table(deAyala) model <- 'F = 1-5 CONSTRAIN = (1-5, a1)' mod <- mirt(dat, model) Theta <- matrix(seq(-6,6,.01)) tscore <- expected.test(mod, Theta) tail(cbind(Theta, tscore)) # use only first two items (i.e., a bundle) bscore <- expected.test(mod, Theta, which.items = 1:2) tail(cbind(Theta, bscore)) ## End(Not run)