arXiv Machine Learning

Diverse Geometries, Frozen Weights: Robust Heterogeneous Treatment-Effect Estimation via Causal Expert Ensembles

The paper introduces GeoACE, a five‑expert framework for estimating heterogeneous treatment effects that blends a common anchor‑correction estimator with overlap‑aware and outcome‑guided geometries. The ensemble’s task‑level weights are learned from internal validation predictions, frozen before test evaluation, and applied to experts refitted on the full development data. Adding the outcome‑free, overlap‑aware expert O‑Phi‑ACE consistently improves performance across seven benchmarks, achieving the lowest average rank among 11 comparators.

arXiv Machine Learning
Jun 10

From Observation to Intervention: A Causal Audit of Expert Importance in Mixture-of-Experts Models

arXiv:2606. 10703v1 Announce Type: new Abstract: Interpretability methods routinely use population-level summary statistics over observed model behaviour to license claims about the effects of targeted interventions on specific computations; in Pearl's terms, they treat rung-1 associational evidence as if it supported rung-2 interventional conclusions, a move whose validity is rarely tested.

By Leonard Engmann, Christian Medeiros Adriano, Holger Giese
arXiv AI
Aug 24

Share the Judge, Learn the Deferral: Where Specialization Helps LLM Evaluation

The paper investigates two strategies for improving large language model (LLM) evaluation: specialized judge weights and rule‑based deferral policies. Experiments on nearly 100,000 rubric‑conditioned samples show that correct rubrics boost accuracy, while incorrect ones hurt it, and that splitting training data into criterion‑specific experts can severely degrade performance unless the experts are warm‑started from a unified model. The authors demonstrate that lightweight deferral cascades can match or exceed the accuracy of larger standalone judges at a fraction of the compute cost, and they provide practical design rules for building efficient, reliable LLM evaluators.

By Ye Chen, Weining Zhang
arXiv Computer Vision
Aug 27

HEDGE: A Calibrated Ensemble for A/H Recognition

arXiv:2607.12176v2 Announce Type: replace Abstract: Ambivalence and hesitancy (A/H) undermine digital behaviour-change interventions, and recognizing them automatically from video is the goal of the...

By Josep Cabacas-Maso, Ismael Benito-Altamirano, Carles Ventura