trailOperational and test data provide evidence about system risk independently of the arguments that cite them
Evidence assembled in a safety argument retains value even if the argument's reasoning is flawed
Direct evidential force of data· for
Statistical inference from operational experience can bound a system's failure rate without a structured assurance argument
Standard statistical methods yield confidence bounds on a system's failure rate from failure-free operational exposure
Statistical testing alone cannot demonstrate the ultra-low failure rates required of safety-critical systems
Assurance-case confidence methods assess trust in evidence separately from trust in the argument's reasoning
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Interpretation dependence· against
The evidential weight of test data for operational risk depends on assumptions about test representativeness
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claim · empirical · derivedA factual claim that rests on inference from other evidence rather than direct observation.constitution →claim page ↗︎
Operational and test data provide evidence about system risk independently of the arguments that cite them
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 →
1depended on by
this rests on ↓
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.