arXiv Machine Learning

BONSAI: Bayesian Optimization with Natural Simplicity and Interpretability

arXiv Machine Learning
Oct 8

Towards Regret Guarantees for One-Step Lookahead Bayesian Optimization

The paper investigates theoretical guarantees for a one‑step lookahead Bayesian optimization method called optimal‑point variance reduction (OVR). It derives a uniform Monte Carlo estimation error bound for the acquisition function and shows that a regularized version of OVR achieves a vanishing Bayesian expected simple regret bound. Numerical experiments validate the performance of both OVR and its regularized variant.

By Shion Takeno
arXiv Statistics ML
Oct 2

IQS-BO: In-Context Query Selection for Bayesian Optimisation

IQS-BO introduces an in‑context query selection method for Bayesian optimisation that learns to choose evaluation points via supervised learning on synthetic priors. The approach uses a Prior‑data Fitted Network (PFN) to predict, in a single forward pass, the probability that each candidate maximises the objective, thereby amortising the decision step and eliminating the need for costly surrogate refitting or acquisition maximisation. Experiments show that IQS‑BO matches or surpasses traditional Gaussian‑process‑based BO and other in‑context methods on both synthetic and real‑world benchmarks, and that a mixture prior combining GP samples with challenging function types further improves performance.

By Luca Geminiani, Nadja Klein