, Volume 25, Issue 2, pp 197–227 | Cite as

A random forest guided tour

  • Gérard Biau
  • Erwan Scornet
Invited Paper


The random forest algorithm, proposed by L. Breiman in 2001, has been extremely successful as a general-purpose classification and regression method. The approach, which combines several randomized decision trees and aggregates their predictions by averaging, has shown excellent performance in settings where the number of variables is much larger than the number of observations. Moreover, it is versatile enough to be applied to large-scale problems, is easily adapted to various ad hoc learning tasks, and returns measures of variable importance. The present article reviews the most recent theoretical and methodological developments for random forests. Emphasis is placed on the mathematical forces driving the algorithm, with special attention given to the selection of parameters, the resampling mechanism, and variable importance measures. This review is intended to provide non-experts easy access to the main ideas.


Random forests Randomization Resampling Parameter tuning Variable importance  

Mathematics Subject Classification




We thank the Editors and three anonymous referees for valuable comments and insightful suggestions.


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Copyright information

© Sociedad de Estadística e Investigación Operativa 2016

Authors and Affiliations

  1. 1.Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Statistique Théorique et Appliquées (LSTA)ParisFrance
  2. 2.Institut universitaire de FranceParisFrance

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