arXiv Machine Learning

Dissecting the Impact of Model Misspecification in Data-driven Optimization

arXiv Machine Learning
3d ago

DisCoMBO: Steering Expert-in-the-Loop Black-Box Optimization via Distributional Conformance

DisCoMBO introduces the Distributional Conformance Score (DisCo), a bounded metric that blends the flexibility of Probabilistic Circuits with formal uncertainty quantification for Sequential Model-Based Optimization. DisCo measures model surprise in a [0,1] range, retaining linear-time inference while enabling accurate assessment of external knowledge conformance. The resulting DisCoMBO framework is proven to be a zero-regret algorithm and shows strong performance on benchmarks in AutoML, material optimization, and wind park optimization.

By Jonas Seng, Bennet Wittelsbach, Kristian Kersting
arXiv Machine Learning
Jun 11

Calibrating Decision Robustness via Inverse Conformal Risk Control

arXiv:2510. 07750v3 Announce Type: replace-cross Abstract: Robust optimization safeguards decisions against uncertainty by optimizing against worst-case scenarios, yet their effectiveness hinges on a prespecified robustness level that is often chosen ad hoc, leading to either insufficient protection or overly conservative and costly solutions.

By Wenbin Zhou, Shixiang Zhu
arXiv Machine Learning
Aug 27

GRAPE: Gradient Refinement and Progress-Aware Exploitation for Query-Efficient High-Dimensional Bayesian Optimization

GRAPE is a two‑stage Bayesian optimization framework that first refines the local gradient posterior using a closed‑form acquisition function and then selects update directions by maximizing expected decrease conditioned on descent. The authors prove that the refinement stage monotonically reduces local uncertainty and that the progress‑aware direction converges to true steepest descent as the posterior sharpens. Empirical results show GRAPE achieves a 5.4× speedup on black‑box adversarial attacks and reduces final average regret by 3.8 log‑units on large language model prompt‑optimization tasks.

By Richard Cornelius Suwandi, Feng Yin
arXiv Statistics ML
5d ago

Contextual Decision Making: Predictive or Generative

The paper compares two strategies for contextual decision making: predict‑then‑optimize (PtO), which learns the conditional expected objective, and generate‑then‑optimize (GtO), which learns conditional uncertainty and optimizes over generated scenarios. It analyzes how the choice of learning target influences statistical accuracy and optimization tractability, showing that smoothness can compensate for GtO’s higher dimensionality. The study also discusses tradeoffs in convexity preservation, scenario‑wise convexity, and model flexibility, supported by synthetic experiments and a real case study.

By L. Jeff Hong, Weihuan Huang, Xinyao Li