Bias estimation and correction in RFSF. Under the null hypothesis (no association between trait and genotypes), RFSF is biased towards variables with low correlation to others (top panel). The bias is estimated by fitting a forest to Gaussian noise, and a correction factor is derived by determining how much more or less frequently a marker is selected than the mean (middle panel). By subtracting the correction factor from the observed RFSF, the selection bias is removed (compare top panel to bottom panel).
Michaelson et al. BMC Genomics 2010 11:502 doi:10.1186/1471-2164-11-502