trailA flawed safety argument provides little evidence about the risk it assesses
The probability of error in a safety argument bounds the confidence it can provide about low-probability risks
Unknown flaw undermines the chain· for
Complex risk analyses historically exhibit error rates exceeding their claimed risk bounds
Pre-Challenger official estimates of Space Shuttle failure risk were far below the realized failure rate
Nuclear probabilistic risk assessments predicted core-damage frequencies well below the observed historical accident rate
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Bank value-at-risk models understated the frequency of extreme losses before the 2008 financial crisis
Regulatory risk assessments commonly use conservative assumptions that overstate risk
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Graceful degradation of arguments· against
Safety arguments with minor flaws often remain approximately correct
Residual assurance deficits in a safety case can be acceptable when compensated by other arguments and evidence
In adversarial settings, small flaws in a safety argument can be exploited into complete failure
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Evidence assembled in a safety argument retains value even if the argument's reasoning is flawed
Operational and test data provide evidence about system risk independently of the arguments that cite them
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Safety cases are prone to confirmation bias toward a predetermined conclusion of safety
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Incomplete hazard identification is a principal cause of safety assurance failures
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Statistical testing alone cannot demonstrate the ultra-low failure rates required of safety-critical systems
claim · empirical · derivedA factual claim that rests on inference from other evidence rather than direct observation.constitution →claim page ↗︎
A flawed safety argument provides little evidence about the risk it assesses
⇄ContestedCredible evidence or argument exists on multiple sides.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.