Step 3: assistant

thinking

Calls update_claim_assessment

{
  "status": "supported",
  "claim_id": "ec9c31d9-8ba5-4107-86f2-25ee089e89a1",
  "assessment": "The claim rests mainly on METR's assessment of 5 November 2026, which had access to Anthropic's internal benchmark scores, including unreleased models. METR estimates that Anthropic's internal capability index has grown at about 1.9 times its earlier rate since October 2025, with a 95% interval of 1.5 to 2.8. Its robustness checks span 1.1 to 2.9, and the low end comes from changing the link function. Anthropic's own Haiku 5.5 system card reports a factor of 1.7. An outside analysis reportedly gets about 1.6 using only public data on released Claude models.\n\nThe evidence shows a speed-up of some size fairly well. The specific figure of \"about twice\" is less firm. The estimates run from roughly 1.6 to 1.9 depending on who measured and on what data, and the low end of the plausible range is near no change. Several things call for caution. The data points are sparse. The breakpoint was fitted, so some regression to the mean should be expected. The index covers well-specified tasks and is increasingly saturated. The primary analysis rests on internal scores that outsiders cannot inspect. Also unresolved is how much of the speed-up is Anthropic catching up to the industry frontier from a below-frontier earlier rate.\n\nA fit on public data would settle more. It would need to vary the break date, the baseline period and the benchmark index, and to compare Anthropic's earlier rate with the frontier's.",
  "confidence": 0.55,
  "claim_credence": 0.65,
  "marginal_yield": 0.7,
  "reasoning_trace": "This pass ran with a very small budget and did not open the primary sources. The figures above come from the note recorded by the Steward of the parent claim, who summarized the METR report of 5 November 2026, Anthropic's Haiku 5.5 system card, and an outside reproduction from public data. That is why confidence is moderate and marginal yield is high.\n\nThe commissioned checks were how far the result can be verified from public data and how sensitive it is to the break date, the baseline and the benchmark index. The only public-data figure is the reported reproduction of about 1.6. METR's own sensitivity range is 1.1 to 2.9, and the low end comes from changing the link function. Sensitivity to the break date and to the choice of benchmark index has not been checked independently. An open request already asks for a public-data refit using the Epoch Capabilities Index, including a comparison with the frontier's earlier rate. That work would decide whether the factor of two holds or whether the speed-up is partly catch-up or an artifact of the fit.\n\nCredence is 0.65 that the rate is \"about twice\", read as roughly 1.6 to 2.4 times. Credence that some real speed-up happened is higher."
}