trailMETR's August 2025 developer productivity experiment yields an unreliable signal of AI's current effect on productivity.
AI tools sped up developers more in early 2026 than early-2025 estimates indicated.
Widespread AI adoption has made AI's effect on task-level productivity harder to measure.
Selection effects from AI-reliant developers opting out bias measured AI productivity speedup estimates downward.
Developers who rely on AI increasingly decline to participate in productivity experiments that require working without AI.
Developers who opt out of AI productivity experiments would experience larger AI speedups than those who participate.
Rising participant selection effects are driven mainly by higher expected AI uplift rather than by the reduced pay rate.
Developers' self-reported estimates of AI-driven productivity speedup are unreliable.
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claim · empirical · derivedA factual claim that rests on inference from other evidence rather than direct observation.constitution →claim page ↗︎
METR's August 2025 developer productivity experiment yields an unreliable signal of AI's current effect on productivity.
↑SupportedEvidence favors the claim, but the chain is incomplete or the sources are secondary.constitution →credence 0.90Credence, from 0 to 1: the Steward's probability that the claim, as stated, is true. Stated only where a single number is an honest summary; normative and evaluative claims usually carry none.constitution →
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claimA box is a claim: a single proposition the graph assesses, with its own page and map. Click any claim to centre the map on it.constitution →argumentA pill is an argument: one line of reasoning stating how the claims beneath it combine to bear on the claim above it, for or against. Arguments are not destinations; click their claims to explore.constitution →✓verifiedThe claim traces to reliable primary sources through a clear chain of evidence.constitution →↑supportedEvidence favors the claim, but the chain is incomplete or the sources are secondary.constitution →⇄contestedCredible evidence or argument exists on multiple sides.constitution →○unsupportedNo credible evidence found, though the claim is not contradicted.constitution →✕contradictedAvailable evidence weighs against the claim.constitution →?unknownInsufficient information to assess.constitution →◌unassessedNo current assessment. Attention goes where its expected value is highest and someone funds it; nothing has funded an assessment of this claim yet, and anyone can.constitution →verified factopen questionvalue premisesupportsthis provides evidence for the parentsteward instructions →contradictsthis argues against the parentsteward instructions →assumesbackground the parent's framing takes as givensteward instructions →requiresa load-bearing premise: the parent is false without itsteward instructions →Fig. Detail falls off with distance; every claim is an address.