5 papers
The Minimax Rate of Second-Order Calibration
Kamil Ciosek, Banafsheh Rafiee, Sina Ghiassian +1
We characterize the minimax rate of estimating the second-order calibration error for binary classification, which quantifies whether a higher-order predictor's epistemic-uncertain…
Measuring Uncertainty Calibration
Kamil Ciosek, Nicolò Felicioni, Sina Ghiassian +6
We make two contributions to the problem of estimating the calibration error of a binary classifier from a finite dataset. First, we provide an upper bound for any classifier…
Hallucination Detection on a Budget: Efficient Bayesian Estimation of Semantic Entropy
Kamil Ciosek, Nicolò Felicioni, Sina Ghiassian
Detecting whether an LLM hallucinates is an important research challenge. One promising way of doing so is to estimate the semantic entropy (Farquhar et al., 2024) of the distribut…
Learning in complex action spaces without policy gradients
Arash Tavakoli, Sina Ghiassian, Nemanja RakiÄeviÄ
While conventional wisdom holds that policy gradient methods are better suited to complex action spaces than action-value methods, foundational work has shown that the two paradigm…
Soft Preference Optimization: Aligning Language Models to Expert Distributions
Arsalan Sharifnassab, Saber Salehkaleybar, Sina Ghiassian +2
We propose Soft Preference Optimization (SPO), a method for aligning generative models, such as Large Language Models (LLMs), with human preferences, without the need for a reward…