CalculateGrmExp: Calculates the expected item score under the GRM model.

CalculateGrmExpR Documentation

Calculates the expected item score under the GRM model.

Description

Calculates the expected item score under the GRM model.

Usage

CalculateGrmExp(thetaValue, itemParameters, logistic = TRUE)

Arguments

thetaValue

A numeric value or array for the theta (ability) value(s) where the difference will be calculated

itemParameters

A matrix containing the numeric values of item discriminations on the first column and category thresholds on the rest columns where the (column position - 1) indicates the category score or weight.

logistic

A logical value stating if the IRT model will use the logistic or the normal metric.

Value

expectedScore A numeric matrix with the expected score on each thetaValue for each item.

Author(s)

Victor H. Cervantes <vhcervantesb at unal.edu.co>

References

de Ayala, R. J., (2009). The theory and practice of item response theory. New York: The Guildford Press

Oshima, T. & Morris, S. (2008). Raju's Differential Functioning of Items and Tests (DFIT). Educational Measurement: Issues and Practice, 27(3), 43–50. doi:10.1111/j.1745-3992.2008.00127.x


herulor/DFIT documentation built on June 25, 2024, 8:23 a.m.