Saved in:
Bibliographic Details
Main Authors: Mao, Anqi, Mohri, Mehryar, Zhong, Yutao
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2405.05968
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910517345386496
author Mao, Anqi
Mohri, Mehryar
Zhong, Yutao
author_facet Mao, Anqi
Mohri, Mehryar
Zhong, Yutao
contents This paper presents a comprehensive analysis of the growth rate of $H$-consistency bounds (and excess error bounds) for various surrogate losses used in classification. We prove a square-root growth rate near zero for smooth margin-based surrogate losses in binary classification, providing both upper and lower bounds under mild assumptions. This result also translates to excess error bounds. Our lower bound requires weaker conditions than those in previous work for excess error bounds, and our upper bound is entirely novel. Moreover, we extend this analysis to multi-class classification with a series of novel results, demonstrating a universal square-root growth rate for smooth comp-sum and constrained losses, covering common choices for training neural networks in multi-class classification. Given this universal rate, we turn to the question of choosing among different surrogate losses. We first examine how $H$-consistency bounds vary across surrogates based on the number of classes. Next, ignoring constants and focusing on behavior near zero, we identify minimizability gaps as the key differentiating factor in these bounds. Thus, we thoroughly analyze these gaps, to guide surrogate loss selection, covering: comparisons across different comp-sum losses, conditions where gaps become zero, and general conditions leading to small gaps. Additionally, we demonstrate the key role of minimizability gaps in comparing excess error bounds and $H$-consistency bounds.
format Preprint
id arxiv_https___arxiv_org_abs_2405_05968
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Universal Growth Rate for Learning with Smooth Surrogate Losses
Mao, Anqi
Mohri, Mehryar
Zhong, Yutao
Machine Learning
This paper presents a comprehensive analysis of the growth rate of $H$-consistency bounds (and excess error bounds) for various surrogate losses used in classification. We prove a square-root growth rate near zero for smooth margin-based surrogate losses in binary classification, providing both upper and lower bounds under mild assumptions. This result also translates to excess error bounds. Our lower bound requires weaker conditions than those in previous work for excess error bounds, and our upper bound is entirely novel. Moreover, we extend this analysis to multi-class classification with a series of novel results, demonstrating a universal square-root growth rate for smooth comp-sum and constrained losses, covering common choices for training neural networks in multi-class classification. Given this universal rate, we turn to the question of choosing among different surrogate losses. We first examine how $H$-consistency bounds vary across surrogates based on the number of classes. Next, ignoring constants and focusing on behavior near zero, we identify minimizability gaps as the key differentiating factor in these bounds. Thus, we thoroughly analyze these gaps, to guide surrogate loss selection, covering: comparisons across different comp-sum losses, conditions where gaps become zero, and general conditions leading to small gaps. Additionally, we demonstrate the key role of minimizability gaps in comparing excess error bounds and $H$-consistency bounds.
title A Universal Growth Rate for Learning with Smooth Surrogate Losses
topic Machine Learning
url https://arxiv.org/abs/2405.05968