K2 Horizon eval breakdown: declines rather than guesses, 26% hallucination rate
ArtificialAnlys · x · 2026-09-03
Artificial Analysis published the full per-eval breakdown of K2 Horizon 375B A23B. Key figure: the model attempts just 40% of AA-Omniscience questions, declining the rest rather than guessing — yielding a 26% hallucination rate, among the lowest measured, with accuracy of 18% essentially unchanged from K2 Think V2 (71% hallucination). The AA-Omniscience Index improved from -40 to -3.
Related event: K2 Horizon Evaluation Details Show 26% Hallucination Rate, Agent Lead(4 posts)→
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