5 papers
Exploration via linearly perturbed loss minimisation
David Janz, Shuai Liu, Alex Ayoub +1
We introduce exploration via linear loss perturbations (EVILL), a randomised exploration method for structured stochastic bandit problems that works by solving for the minimiser of…
Learning What to Recommend: Minimax Optimal Simple Regret in Logistic Bandits
Shuai Liu, Alireza Bakhtiari, Alex Ayoub +2
We study stochastic logistic bandits with -dimensional action features under the simple-regret objective, where a learner uses rounds of exploration to output a single final…
Bernstein-type dimension-free concentration for self-normalised martingales
Arya Akhavan, Amitis Shidani, Alex Ayoub +1
We introduce a dimension-free Bernstein-type tail inequality for self-normalised martingales, where the normalisation uses the predictable quadratic variation and the radius depend…
Eluder dimension: localise it!
Alireza Bakhtiari, Alex Ayoub, Samuel Robertson +2
We establish a lower bound on the eluder dimension of generalised linear model classes, showing that standard eluder dimension-based analysis cannot lead to first-order regret boun…
Does Weighting Improve Matrix Factorization for Recommender Systems?
Alex Ayoub, Samuel Robertson, Dawen Liang +2
Matrix factorization is a widely used approach for top-N recommendation and collaborative filtering. When implemented on implicit feedback data (such as clicks), a common heuristic…