BED-LLM: Intelligent Information Gathering with LLMs and Bayesian Experimental Design

Published: 26 Jan 2026, Last Modified: 11 Apr 2026ICLR 2026 PosterEveryoneRevisionsBibTeXCC BY 4.0
Keywords: experimental design, Bayesian experimental design, BED, expected information gain, EIG, information gain, Bayesian, uncertainty, LLM, conversational agent, clarification, question asking
Abstract: We propose a general-purpose approach for improving the ability of large language models (LLMs) to intelligently and adaptively gather information from a user or other external source using the framework of sequential Bayesian experimental design (BED). This enables LLMs to act as effective multi-turn conversational agents and interactively interface with external environments. Our approach, which we call BED-LLM (Bayesian experimental design with large language models), is based on iteratively choosing questions or queries that maximize the expected information gain (EIG) with respect to a variable of interest given the responses gathered previously. We show how this EIG can be formulated (and then estimated) in a principled way using a probabilistic model derived from the LLM's predictive distributions and provide detailed insights into key decisions in its construction and updating procedure. We find that BED-LLM achieves substantial gains in performance across a wide range of tests based on the 20 Questions game and using the LLM to actively infer user preferences, compared to purely prompting-based design generation and other adaptive design strategies.
Primary Area: foundation or frontier models, including LLMs
Submission Number: 6176
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