Computes the reliability of a scale with r2 measurements given the reliability of a scale with r1 measurements

Computes the reliability of a scale that is the sum or average of r2 parallel measurements given the reliability of a scale that is the sum or average of r1 parallel measurements. The "measurements" can be items, forms, raters, or occasions.

For more details, see Section 4.19 of Bonett (2021, Volume 1)

Usage

spearmanbrown(rel, r1, r2)

Arguments

rel

reliability of the sum or average of r1 measurements

r1

number of measurements in the original scale

r2

number of measurements in the new scale

Value

Returns the reliability of the sum or average of r2 measurements

References

Bonett DG (2021). Statistical Methods for Psychologists https://dgbonett.sites.ucsc.edu/.

Examples

spearmanbrown(.6, 10, 20)
#>  Reliability of r2 measurements
#>                            0.75

# Should return:
# Reliability of r2 measurements
#                            .75