Noesion Radarnoesion.ai
Research2026-08-10

Independent researcher Shrivu Shankar published an API-probing study estimating pre-training timelines for frontier Anthropic and OpenAI models. Using an 8-way multiple-choice quiz built from Wikipedia daily-facts pages, he plotted error rates over time to infer effective knowledge cutoffs, concluding that Anthropic models from Opus 4.7 onward appear to share a single pre-training run cutting off around late December 2025, and that OpenAI's GPT-5.6 family derives from a separate checkpoint finishing around late February 2026. Opus 5 is flagged as anomalous: its published reliable and overall cutoffs are May 2026, yet it recalls little beyond January 2026, including on coding package versions.

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