EX-14 · Beat the reranker

Difficulty: 🔴 · label difficulty: 3 Stuck? Ask in the clinic thread for EX-14 — one long-running thread per exercise, so the answers accumulate where the next person will look. Submit: post it in Show and Tell titled [solution · EX-14] ..., with your numbers and your interval.

Notebook 04 · ~3 h · Seam ⑤ · Skill: fit, verify, and be honest

Improve ProxyCrossEncoder. Add features, change the model class, or replace it with a real cross-encoder if you have the dependency.

Acceptance criteria

• Fitted on dev only; frozen slice looked at once
• Evidence recall and full-chain recall, each with an interval
• Added latency measured, not estimated
• If your gain does not clear the noise band, say so — that is a passing submission

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