In this paper we establish a new margin-based generalization bound for voting classifiers, refining existing results and yielding tighter generalization guarantees for widely used boosting algorithms such as AdaBoost (Freund and Schapire, 1997). Furthermore, the new margin-based generalization bound enables the derivation of an optimal weak-to-strong learner: a Majority-of-3 large-margin classifiers with an expected error matching the theoretical lower bound. This result provides a more natural alternative to the Majority-of-5 algorithm by (H\o gsgaard et al. 2024) , and matches the Majority-of-3 result by (Aden-Ali et al. 2024) for the realizable prediction model.
翻译:本文为投票分类器建立了一种新的基于间隔的泛化界,改进了现有结果,并为广泛使用的提升算法(如AdaBoost)提供了更紧的泛化保证。此外,新的基于间隔的泛化界使得推导一种最优的弱到强学习器成为可能:一个由三个大间隔分类器构成的多数投票集成,其期望误差与理论下界相匹配。该结果为(Høgsgaard等人,2024)提出的“多数-5”算法提供了一种更自然的替代方案,并且在可实现预测模型下,与(Aden-Ali等人,2024)的“多数-3”结果相一致。