arXiv AI By Christos Petridis, Konstantinos Pelechrinis, Zoran Obradovic

How Unlikely Is "Unlikely"? Assessing Verbal Probability Perception Across Large Language Models

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The study evaluates how large language models (LLMs) interpret verbal probability expressions by mapping words to numbers and testing consistency across 19 models. Results show that LLMs largely mirror human benchmarks—preserving word order, recovering key anchor points, and reflecting the high variance of the term "possible"—but they exhibit a systematic upward bias for negative expressions like "unlikely" and "improbable." Explanation elicitation reduces within‑model variance but increases divergence between models, while a bidirectional roundtrip test reveals that leading models maintain coherent internal representations.

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