A class of simple adaptive allocation rules is proposed for the problem (often called the "multi-armed bandit problem") of sampling $x_1, \cdots x_N$ sequentially from $k$ populations with densities belonging to an exponential family, in order to maximize the expected value of the sum $S_N = x_1 + \cdots + x_N$. These allocation rules are based on certain upper confidence bounds, which are developed from boundary crossing theory, for the $k$ population parameters. The rules are shown to be asymptotically optimal as $N \rightarrow \infty$ from both Bayesian and frequentist points of view. Monte Carlo studies show that they also perform very well for moderate values of the horizon $N$.
@article{1176350495,
author = {Lai, Tze Leung},
title = {Adaptive Treatment Allocation and the Multi-Armed Bandit Problem},
journal = {Ann. Statist.},
volume = {15},
number = {1},
year = {1987},
pages = { 1091-1114},
language = {en},
url = {http://dml.mathdoc.fr/item/1176350495}
}
Lai, Tze Leung. Adaptive Treatment Allocation and the Multi-Armed Bandit Problem. Ann. Statist., Tome 15 (1987) no. 1, pp. 1091-1114. http://gdmltest.u-ga.fr/item/1176350495/