A tutorial on learning from preferences and choices with Gaussian Processes
Alessio Benavoli, Dario Azzimonti
TL;DR
This work presents a unified Gaussian Process framework for learning from preferences and choices, covering object and label data as well as choice behavior. It introduces nine GP-based models that accommodate rational utilities, random utility perturbations, discernibility limits, multiple utilities, and two-argument representations, along with extensions to label rankings and paired comparisons. The approach relies on flexible likelihoods (probit, Thurstone, Plackett–Luce, etc.) atop GP priors, enabling uncertainty quantification and scalable inference via inducing points and approximate methods; a prefGP library is provided for practical deployment. Applications span transportation mode selection, gaming platform rankings, subjective judgments (ellipses), and recommender systems (MovieLens), illustrating both predictive accuracy and interpretability of latent utilities. The work highlights connections to preferential Bayesian optimization and outlines future directions, including mixed data sources and monotonicity/convexity constraints to further enhance model fidelity and applicability.
Abstract
Preference modelling lies at the intersection of economics, decision theory, machine learning and statistics. By understanding individuals' preferences and how they make choices, we can build products that closely match their expectations, paving the way for more efficient and personalised applications across a wide range of domains. The objective of this tutorial is to present a cohesive and comprehensive framework for preference learning with Gaussian Processes (GPs), demonstrating how to seamlessly incorporate rationality principles (from economics and decision theory) into the learning process. By suitably tailoring the likelihood function, this framework enables the construction of preference learning models that encompass random utility models, limits of discernment, and scenarios with multiple conflicting utilities for both object- and label-preference. This tutorial builds upon established research while simultaneously introducing some novel GP-based models to address specific gaps in the existing literature.
