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arXiv:2406.03689cs.CL

Evaluating the World Model Implicit in a Generative Model

Keyon Vafa, Justin Y. Chen, Ashesh Rambachan, Jon Kleinberg, Sendhil Mullainathan

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Abstract

Recent work suggests that large language models may implicitly learn world models. How should we assess this possibility? We formalize this question for the case where the underlying reality is governed by a deterministic finite automaton. This includes problems as diverse as simple logical reasoning, geographic navigation, game-playing, and chemistry. We propose new evaluation metrics for world model recovery inspired by the classic Myhill-Nerode theorem from language theory. We illustrate their utility in three domains: game playing, logic puzzles, and navigation. In all domains, the generative models we consider do well on existing diagnostics for assessing world models, but our evaluation metrics reveal their world models to be far less coherent than they appear. Such incoherence creates fragility: using a generative model to solve related but subtly different tasks can lead to failures. Building generative models that meaningfully capture the underlying logic of the domains they model would be immensely valuable; our results suggest new ways to assess how close a given model is to that goal.

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DOI
Subjects
cs.CLComputation and Language cs.AIArtificial Intelligence

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Linked by 1 identifiable commenter in 4 comments across 3 threads, from Aug 2025 to Oct 2025. Found in 2 HN submissions from Jun 2024 to Nov 2024. Open submission discussions.

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Discussed in comments3 threads

    • > any human who ever lived Is this falsifiable? Even restricting to those currently living? On what tests? In which way? Does the category of error matter? > can you name one functional difference between an AI that understands, and one that merely behaves correctly in its…

      godelskiView on HNParent context

    • > What if language is the intelligence? Almost certainly not. There does not seem to be a strong correlation between the two. We have a lot of different measures for intelligence when it comes to animals. We can place them across a (multidimensional) spectrum and humans seem…

      godelskiView on HNParent context

    • > Doesn't this then support the claim that LLMs aren't building world models There's actually no strong evidence that LLMs, or any AI system, is actually building a world model. These systems are determined to have "world model" capabilities based on benchmarks, but benchmarks…

      godelskiView on HNParent context

    • > That's not a contradiction? Correct. No contradiction was intended. As you quote, I wrote "It's not just that". This is not setting up a contrasting point, this is setting up a point that follows. Which, as you point out, does follow. So let me rephrase > If all models are…

      godelskiView on HNParent context

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