# DEFENSIBILITY FOUR REQUIREMENTS -- Checklist

**Scope:** Gate for any "nothing found" record. ALL FOUR must be checked PRESENT before emission. If any is absent, the record is invalid, stopping is rescinded, skill returns to Phase B.

Grounding: Altman & Bland (BMJ 1995); Cochrane Ch. 4 + Ch. 13; JCE (2025) documents ~54% of trials misinterpret null as "no effect."

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## The checklist

Run at Phase G, per claim, BEFORE emission. Authoritative; spirit is not sufficient.

### [ ] Requirement 1 -- Pre-registered inversion classes exercised

- [ ] IC-1 Boundary-Condition Inversion: status recorded as `exercised` (with query-ids) OR `non-applicable` (with reason).
- [ ] IC-2 Alternative-Explanation Inversion: status recorded as `exercised` (with query-ids) OR `non-applicable` (with reason).
- [ ] IC-3 Replication-Failure Inversion: status recorded as `exercised` (with query-ids) OR `non-applicable` (with reason).
- [ ] IC-4 Frame / Construct Inversion: status recorded as `exercised` (with query-ids) OR `non-applicable` (with reason).
- [ ] No class marked `skipped`, `deferred`, `time-boxed`, or `N/A without reason`.

Failure mode this catches: lazy close with hidden uncovered classes.

### [ ] Requirement 2 -- Coverage outcome per class

For each `exercised` class, the record states:
- [ ] Queries issued (query-ids list, not a count).
- [ ] Sources surfaced pre-integrity-screen.
- [ ] Sources accepted post-S2 integrity screen.
- [ ] Disconfirmation categories detected -- list the categories; `[]` (explicit empty list) if none. NEVER write "zero."

For each `non-applicable` class:
- [ ] Non-applicability reasoning logged to Ledger with specific rationale (e.g., "IC-3 non-applicable: novel operationalization, no prior replications; absence-of-priors logged as SR-<id>").

Failure mode caught: "coverage" asserted without per-class accounting.

### [ ] Requirement 3 -- Saturation evidence per class

For each `exercised` class:
- [ ] Saturation rule named: "K consecutive null-or-known-category queries."
- [ ] K value stated (3 for IC-1/IC-2/IC-3; 2 for IC-4; other K requires justification).
- [ ] Specific consecutive queries that triggered saturation are query-id-listed.
- [ ] Stopping cause is per-class saturation. NEVER "query budget," "time budget," "token budget," or any count divorced from saturation evidence.

`non-applicable` classes: satisfied by Requirement 2 documentation.

Failure mode caught: volume-floor regression disguised as saturation.

### [ ] Requirement 4 -- Uncertainty-interval framing

Record contains all four elements verbatim:
- [ ] "No disconfirming evidence detected under this search."
- [ ] "Absence of evidence is not evidence of absence (Altman & Bland, BMJ 1995)."
- [ ] "Inversion space covered:" followed by per-IC-class scope enumeration.
- [ ] "Inversion space NOT covered:" followed by explicit gaps -- corpora not searched, languages, grey-literature surfaces unavailable, non-applicable classes, unsearchable adjacent literatures, paywall / preprint exclusions.

Failure mode caught: "nothing found" with no scope-conditioning.

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## Gate semantics

- All four boxes checked -> valid; emit record; signal Warrant Governor `defensibly-closed`.
- Any box unchecked -> invalid; rescind stopping; return to Phase B.

Phase 9 Evaluator audit: checklist entries referencing query-ids without matching Ledger rows are a ceremonial-pattern signal and trigger full rerun.
