test_prop function

Properties of the Test

Information summarizing measurement quality of the test and test targeting.

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.

Returns

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

Examples

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

References

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

Author(s)

Marianne Mueller