Function that gives the attenuated R for an unattenuated R and two reliability values

This is just the conventional formula for the attenuation of a (Pearson) correlation by unreliability.

Usage

getAttenuatedR(unattR, rel1, rel2, dp = 3)

Arguments

unattR

unattenuated R

rel1

reliability of first of the variables (order of variables is arbitrary)

rel2

reliability of second of the variables (order of variables is arbitrary)

dp

number of decimal places required for attenuated R

Value

numeric: attenuated correlation

Background

This is ancient psychometrics but still of some use. For more information, see: OMbook glossary entry for attenuation The formula is simple:

attenuatedCorr=unattenuatedCorr*rel_1*rel_2attenuatedR = unattR * sqrt(rel1 * rel2)

The short summary is that unreliability in the measurement of both variables involved in a correlation always reduces the observed correlation between the variables from what it would have been had the variables been measured with no unreliability (which is essentially impossible for any self-report measures and pretty much any measures used in our fields.

History/development log

Started 12.x.24

See also

Other utility functions: convertClipboardAuthorNames(), fixVarNames(), getCorrectedR(), whichSetOfN()

Author

Chris Evans

Examples

getAttenuatedR(.9, .7, .8)
#> [1] 0.673