Parameter-Free Online Learning via Model Selection

Authors: Dylan J. Foster, Satyen Kale, Mehryar Mohri, Karthik Sridharan

NeurIPS 2017 | Conference PDF | Archive PDF | Plain Text | LLM Run Details

Reproducibility Variable Result LLM Response
Research Type Theoretical We introduce an efficient algorithmic framework for model selection in online learning, also known as parameter-free online learning. Departing from previous work, which has focused on highly structured function classes such as nested balls in Hilbert space, we propose a generic meta-algorithm framework that achieves online model selection oracle inequalities under minimal structural assumptions. We give the first computationally efficient parameter-free algorithms that work in arbitrary Banach spaces under mild smoothness assumptions; previous results applied only to Hilbert spaces. We further derive new oracle inequalities for matrix classes, non-nested convex sets, and Rd with generic regularizers. Finally, we generalize these results by providing oracle inequalities for arbitrary non-linear classes in the online supervised learning model. These results are all derived through a unified meta-algorithm scheme using a novel multi-scale algorithm for prediction with expert advice based on random playout, which may be of independent interest.
Researcher Affiliation Collaboration Dylan J. Foster Cornell University Satyen Kale Google Research Mehryar Mohri NYU and Google Research Karthik Sridharan Cornell University
Pseudocode Yes Algorithm 3 procedure MULTISCALEFTPL(c, ) Scale vector c with ci 1, prior distribution . for time t = 1,...,n: do Draw sign vectors σt+1,...,σn { 1}N each uniformly at random. Compute distribution pt(σt+1 n) = arg min sup gt gt[i] ci σs[i]ci B(i) where B(i) = 5ci i n i . Play it pt. Observe loss vector gt. end for end procedure
Open Source Code No The paper does not contain any statement about making its source code publicly available or providing a link to a code repository.
Open Datasets No The paper is theoretical and does not mention the use of any datasets for training or evaluation, nor does it provide access information for any publicly available dataset.
Dataset Splits No The paper is theoretical and does not describe any dataset splits (training, validation, or test) as it does not involve empirical experiments.
Hardware Specification No The paper is theoretical and does not describe any hardware used for experiments.
Software Dependencies No The paper is theoretical and does not specify any software dependencies with version numbers.
Experiment Setup No The paper is theoretical and does not describe any experimental setup details such as hyperparameters or training configurations.