Run #003 surfaced rampant cross-pollination: Q2's "OSHA-30 forklift
Wisconsin" recording (w-4435) became warm top-1 for Q19 (dental
hygienist), Q20 (RN), Q21 (software engineer), and 6 other unrelated
staffing queries. Cause: InjectPlaybookMisses inherited the same
DefaultPlaybookMaxDistance (0.5) as the boost path, but inject is
structurally riskier than boost — boost only re-ranks results that
already retrieved on their own merits, while inject FORCES a result
into top-K, so a loose match cross-pollinates wrong-domain answers.
Empirical motivation from v3:
Implied playbook hit distances for cross-pollinated cases: 0.20-0.46
Implied distances for the 6/6 paraphrase recoveries: 0.23-0.30
Threshold of 0.20 should keep most paraphrases, kill the OOD bleed.
Implementation:
- New DefaultPlaybookMaxInjectDistance = 0.20 in playbook.go.
- New PlaybookMaxInjectDistance field on SearchRequest (override).
- InjectPlaybookMisses signature gains maxInjectDist param; hits whose
Distance exceeds it are skipped (boost path may still re-rank them).
- TestInjectPlaybookMisses_RespectsInjectThreshold locks the contract
with one tight + one loose hit, asserting only the tight one injects.
- Existing tests pass explicit threshold (0 = default for tight tests,
0.5 for the dedupe test which uses 0.30 hits).
Run #004 result on identical queries with the split threshold:
Verbatim discovery 8 (vs v3's 6 — judge variance, separate)
Verbatim lift 6 / 8 (75%)
Paraphrase top-1 6 / 8 (75%)
Paraphrase any-rank in K 6 / 8
OOD queries Q19/Q20/Q21 ALL show warm top-1 = cold top-1 (no
injection) — cross-pollination eliminated where it was wrong-direction.
Mean Δ top-1 distance dropped from -0.164 (v3, distorted) to -0.071
(v4, comparable to v1's -0.053).
Two paraphrases missed in v4 (Q9, Q15) were ones where qwen2.5
rephrased liberally enough to drift past 0.20 — Q9: "Inventory
specialist..." → "Individual needed for inventory management..." and
Q15: "Engaged warehouse associate..." → "Warehouse associate currently
engaged with a robust history...". The system correctly refusing to
inject when it's not confident is the right product behavior; the
boost path still re-ranks recorded answers when they appear in regular
retrieval.
The Q6 ↔ Q7 cross-pollination ("Forklift-certified loader" ↔
"Hazmat warehouse worker") is legitimate — these are genuinely similar
staffing queries and the judge ranks both directions as plausible.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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