An Asymptotically Optimal Batched Algorithm for the Dueling Bandit
Problem
- URL: http://arxiv.org/abs/2209.12108v1
- Date: Sun, 25 Sep 2022 00:23:55 GMT
- Title: An Asymptotically Optimal Batched Algorithm for the Dueling Bandit
Problem
- Authors: Arpit Agarwal, Rohan Ghuge, Viswanath Nagarajan
- Abstract summary: We study the $K$-armed dueling bandit problem, a variation of the traditional multi-armed bandit problem in which feedback is obtained in the form of pairwise comparisons.
We obtain regret of $O(K2log(K)) + O(Klog(T))$ in $O(log(T))$ rounds, where $T$ is the time horizon.
In computational experiments over a variety of real-world datasets, we observe that our algorithm using $O(log(T))$ rounds achieves almost the same performance as fully
- Score: 13.69077222007053
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We study the $K$-armed dueling bandit problem, a variation of the traditional
multi-armed bandit problem in which feedback is obtained in the form of
pairwise comparisons. Previous learning algorithms have focused on the
$\textit{fully adaptive}$ setting, where the algorithm can make updates after
every comparison. The "batched" dueling bandit problem is motivated by
large-scale applications like web search ranking and recommendation systems,
where performing sequential updates may be infeasible. In this work, we ask:
$\textit{is there a solution using only a few adaptive rounds that matches the
asymptotic regret bounds of the best sequential algorithms for $K$-armed
dueling bandits?}$ We answer this in the affirmative $\textit{under the
Condorcet condition}$, a standard setting of the $K$-armed dueling bandit
problem. We obtain asymptotic regret of $O(K^2\log^2(K)) + O(K\log(T))$ in
$O(\log(T))$ rounds, where $T$ is the time horizon. Our regret bounds nearly
match the best regret bounds known in the fully sequential setting under the
Condorcet condition. Finally, in computational experiments over a variety of
real-world datasets, we observe that our algorithm using $O(\log(T))$ rounds
achieves almost the same performance as fully sequential algorithms (that use
$T$ rounds).
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