Smoothed Online Classification can be Harder than Batch Classification

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Raman, Vinod, Subedi, Unique, Tewari, Ambuj
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909210029064192
author Raman, Vinod
Subedi, Unique
Tewari, Ambuj
author_facet Raman, Vinod
Subedi, Unique
Tewari, Ambuj
contents We study online classification under smoothed adversaries. In this setting, at each time point, the adversary draws an example from a distribution that has a bounded density with respect to a fixed base measure, which is known apriori to the learner. For binary classification and scalar-valued regression, previous works \citep{haghtalab2020smoothed, block2022smoothed} have shown that smoothed online learning is as easy as learning in the iid batch setting under PAC model. However, we show that smoothed online classification can be harder than the iid batch classification when the label space is unbounded. In particular, we construct a hypothesis class that is learnable in the iid batch setting under the PAC model but is not learnable under the smoothed online model. Finally, we identify a condition that ensures that the PAC learnability of a hypothesis class is sufficient for its smoothed online learnability.
format Preprint
id arxiv_https___arxiv_org_abs_2405_15424
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Smoothed Online Classification can be Harder than Batch Classification
Raman, Vinod
Subedi, Unique
Tewari, Ambuj
Machine Learning
We study online classification under smoothed adversaries. In this setting, at each time point, the adversary draws an example from a distribution that has a bounded density with respect to a fixed base measure, which is known apriori to the learner. For binary classification and scalar-valued regression, previous works \citep{haghtalab2020smoothed, block2022smoothed} have shown that smoothed online learning is as easy as learning in the iid batch setting under PAC model. However, we show that smoothed online classification can be harder than the iid batch classification when the label space is unbounded. In particular, we construct a hypothesis class that is learnable in the iid batch setting under the PAC model but is not learnable under the smoothed online model. Finally, we identify a condition that ensures that the PAC learnability of a hypothesis class is sufficient for its smoothed online learnability.
title Smoothed Online Classification can be Harder than Batch Classification
topic Machine Learning
url https://arxiv.org/abs/2405.15424