Reliability of a weighted composite (Mosier, 1943; Lord & Novick, 1968)

Reliability of a weighted composite (Mosier, 1943; Lord & Novick, 1968)

Usage

fuse_reliability(weights, item_cor, item_reliabilities = NULL)

Arguments

weights

Numeric vector of composite weights.

item_cor

Symmetric correlation (or covariance) matrix among items.

item_reliabilities

Numeric vector of item reliabilities (length equal to weights). If NULL, the composite reliability is computed under the assumption that diagonal entries of item_cor are item reliabilities (e.g., when an empirical reliability matrix is supplied).

Value

The reliability of the weighted composite.

References

Lord, F. M., & Novick, M. R. (1968). Statistical theories of mental test scores. Addison-Wesley.

Mosier, C. I. (1943). On the reliability of a weighted composite. Psychometrika, 8, 161-168.

Examples

R <- matrix(c(1, .3, .3, 1), 2, 2)
fuse_reliability(c(.5, .5), R, item_reliabilities = c(.80, .85))
#> [1] 0.8653846