Correction for attenuation
is a statistical procedure, due to Spearman
, to "rid a correlation
coefficient from the weakening effect of measurement error" (Jensen, 1998).
Given two random variables and , with correlation , and a known reliability for each variable, and , the correlation between and corrected for attenuation is
How well the variables are measured affects the correlation of X and Y. The correction for attenuation tells you what the correlation would be if you could measure X and Y with perfect reliability.
If and are taken to be imperfect measurements of underlying variables and with independent errors, then measures the true correlation between and .
- Jensen, A.R. (1998). The g Factor. Praeger, Connecticut, USA.