The correlation between two variables after allowing for the effect of other variables. For variables A, B, and C, with, for example, rAB denoting the correlation coefficient between A and B, the partial correlation coefficient between A and B allowing for C is rAB|C, given by![partial correlation](Images/oree/doc/10.1093/acref/9780199679188.001.0001/acref-9780199679188-math-0500-full.gif)