Selection and scope effects
The argument
Because safety cases tend to select evidence to support a predetermined conclusion of safety, the assembled evidence is not a neutral sample of what is known about the system, and because the flaws that defeat safety assurance are principally missed hazards, the evidence a flawed case contains is often aimed at the wrong risks entirely; on both counts, discovering the flaw should sharply discount the standalone value of the evidence the same authors chose to present.
Does it work?
Not yet evaluated.
Premises
- SupportedThe evidence favors the claim, but the examination is incomplete or the evidence is indirect.constitution →Safety cases are prone to confirmation bias toward a predetermined conclusion of safety
- SupportedThe evidence favors the claim, but the examination is incomplete or the evidence is indirect.constitution →Incomplete hazard identification is a principal cause of safety assurance failures
Where it is made
Passages where sources make, criticize or mention this argument. They record where it appears, not how strong it is, and none has precedence over another.
No source is recorded as making it.
Earlier ratings
- Jul 25, 2026
Granting its premises, the argument establishes a real and sometimes severe discount on the surviving evidence, but not the conclusion that no value is retained: even a selectively assembled body of genuine test and field data constrains the risk estimate. Its weight rests chiefly on the confirmation-bias tendency of safety cases, which is a live critique rather than a settled finding, and on missed hazards being a principal cause of assurance failures, which bites only when the flaw is of that kind. The argument therefore qualifies the claim's scope rather than defeating it.