Using Random Forests to scan for loci involved in oligogenetic disease Peter Kraft 12 Dec 2002 Random Forests [L Breiman, Machine Learning 45:5-32] are a novel supervised learning method well-suited for data with many covariates but relatively few observations. The fitting procedure produces estimates of prediction error, variable importance, and observation proximity. Random forests can also be used in an unsupervised context to produce a matrix of intrinsic proximities among observations. I review the basics of Random Forests and present an application in genetic epidemiology: detecting interactions among a few loci from a large set of (mostly inert) candidate loci in a simulated case- control study.