METR Tests Claude Opus 5.5 as Cheating Benchmarks Bite — September 23, 2026
Claude Opus 5.5 gets METR’s predeployment look at AI R&D acceleration while new reward-hacking work and CAIS CheatBench press on whether scores still track real task quality. CNAS argues any U.S.-China safety deal will need verification, not trust.
In this episode
Summary of METR's predeployment evaluation of Claude Opus 5.5 — METR
Note on independence: This evaluation was conducted under an unpaid agreement for AI R&D assessment. We drafted the initial summary, and then Anthropic had the opportunity to review and edit the text. We signed off on this final text from the Claude Opus 5.5 system…
The skinny
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