test_prop {iarm}

Properties of the Test

Description

Information summarizing measurement quality of the test and test targeting.

Usage

test_prop(object)

Arguments

object

An object of class "Rm", a fitted Rasch model or partial credit model using the functions RM or PCM in package eRm, or an object of class "pcmodel", a fitted partial credit model using the function pcmodel in package psychotools.

Value

a list containing:

Separation reliability

the person separation reliability as calculated in package eRm for objects of class "Rm".

Test difficulty

person value with an expected score equal to half of the maximum score.

Test target

person value where test information is maximized.

Test information

maximal value of the test information

Author(s)

Marianne Mueller

References

Christensen, K. B. , Kreiner, S. & Mesbah, M. (Eds.) Rasch Models in Health. Iste and Wiley (2013), pp. 63 - 70.

Examples

rm.mod <- RM(amts[,4:13])
test_prop(rm.mod)