grm_iif {exametrika} | R Documentation |
Item Information Function for GRM
Description
Calculates the value of the Item Information Function for the Graded Response Model.
Usage
grm_iif(theta, a, b)
Arguments
theta |
Latent trait value of the subject |
a |
Discrimination parameter of IRF |
b |
Vector of difficulty parameters (thresholds) of IRF |
Value
Value of the Item Information Function
Examples
## Not run:
# Example for an item with 3 categories
a <- 1.5
b <- c(-1.0, 1.0)
thetas <- seq(-3, 3, by = 0.1)
info <- sapply(thetas, function(t) grm_iif(t, a, b))
plot(thetas, info, type = "l", xlab = "Theta", ylab = "Information")
## End(Not run)
[Package exametrika version 1.5.1 Index]