What is "boosting"

Boost \Boost\ (b[=oo]st), v. t. [imp. & p. p. Boosted; p. pr. & vb. n. Boosting.] [Cf. Boast, v. i.] To lift or push from behind (one who is endeavoring to climb); to push up; hence, to assist in overcoming obstacles, or in making advancement. [Colloq. U. S.]

vb. (present participle of boost English)

Boosting is a machine learning ensemble meta-algorithm for primarily reducing bias, and also variance in supervised learning, and a family of machine learning algorithms which convert weak learners to strong ones. Boosting is based on the question posed by Kearns and Valiant (1988, 1989) : Can a set of weak learners create a single strong learner? A weak learner is defined to be a classifier which is only slightly correlated with the true classification (it can label examples better than random guessing). In contrast, a strong learner is a classifier that is arbitrarily well-correlated with the true classification.

Robert Schapire's affirmative answer in a 1990 paper to the question of Kearns and Valiant has had significant ramifications in machine learning and statistics, most notably leading to the development of boosting.

When first introduced, the hypothesis boosting problem simply referred to the process of turning a weak learner into a strong learner. "Informally, [the hypothesis boosting] problem asks whether an efficient learning algorithm […] that outputs a hypothesis whose performance is only slightly better than random guessing [i.e. a weak learner] implies the existence of an efficient algorithm that outputs a hypothesis of arbitrary accuracy [i.e. a strong learner]." Algorithms that achieve hypothesis boosting quickly became simply known as "boosting". Freund and Schapire's arcing (Adapt[at]ive Resampling and Combining), as a general technique, is more or less synonymous with boosting.

Boosting is a method of inducing autonomic dysreflexia with the intention of enhancing performance in sport. It can be used by an athlete with a spinal cord injury to increase their blood pressure and is performed by causing a painful stimulus in the lower part of the body. The International Paralympic Committee (IPC) banned the practice in 1994, but many competitors with spinal injuries are still thought to be using it as a performance enhancer.