Abstract An AI assessor is an external, ideally independent system that predicts an indicator, e.g., a loss value, of another AI system. Assessors can leverage information from the test results of many other AI systems and have the flexibility of being trained on any loss function or scoring rule: from squared error to toxicity metrics. Here we address the question: is it always optimal to train the assessor for the target metric? Or could it be better to train for a different metric and then map predictions back to the target metric? Using twenty regression and classification problems with tabular data, we experimentally explore this question for, respectively, regression losses and classification scores with monotonic and nonmonotonic mappings and find that, contrary to intuition, optimising for more informative metrics (i.e., yielding a better-conditioned supervision signal) is not universally preferred. Surprisingly, some monotonic transformations are promising. For example, logistic loss is useful for minimising absolute or quadratic errors in regression, and logarithmic score helps maximise quadratic or spherical scores in classification.
Abstract We show that for unconstrained Deep Linear Discriminant Analysis (LDA) classifiers, maximum-likelihood training admits pathological solutions in which class means drift together, covariances collapse, and the learned representation becomes almost non-discriminative. Conv…
Abstract In today’s digital landscape, user-generated opinions—such as online reviews, user comments, and social media posts—offer valuable insights into people’s experiences, sentiments, and concerns, influencing decisions across businesses, organizations, and public policy. Adv…
Abstract Simulating physical systems is essential in engineering, but analytical solutions are limited to straightforward problems. Consequently, numerical methods like the Finite Element Method (FEM) are widely used. However, the FEM becomes computationally expensive as problem…
Abstract While most continual learning methods focus on mitigating forgetting and improving accuracy, they often overlook the critical aspect of network calibration, despite its importance. Neural collapse, a phenomenon where last-layer features collapse to their class means, has…
Abstract Modeling the temporal evolution of biological systems is fundamental for understanding cellular dynamics and anticipating future functional states. While temporal graph neural networks (TGNNs) have achieved remarkable success in social and financial domains, their evalua…
Abstract Learning-based approaches have made substantial progress on solving combinatorial optimization problems, increasingly rivaling classical operations research methods. In particular, improvement-based machine learning methods, which iteratively refine an existing solution,…