Tune Anchors

tune-anchors

The objective

Given a writing-voice/ corpus and one or more target articles, answer: which anchor-selection rule produces rewrites closest to the author's own register?

A rule is an arm — a set of filters over the manifest: role=venue-voice, tags~clipped, pre_ai=true. Different arms produce different anchor sets, and the model copies the register of whatever it sees. The right arm is the one whose anchors give the model a register worth copying.

The pipeline

Each full trial runs two model passes before measurement:

1. match-voice (drive.py) — voice rewrite using the arm's anchors
2. tighten-style (tighten.py) — remove AI-register artifacts (passive stacks, nominalizations, filler) using the same model family shown transformation pairs, not rules
3. measure — register markers on the tightened output

The ranking reflects the final output quality, not the raw voice draft. Tightening is what removes the AI sound; ranking without it would penalize arms whose raw drafts carry fixable markers and reward arms whose markers survive tightening unchanged.

--no-tighten skips step 2 and measures the raw voice draft instead. Use it to isolate the voice effect or to compare the tighten delta across arms.

When to run

• Writing-voice onboarding. After the manifest exists and before the first real rewrite. Output is the --anchor-tags query to use thereafter.
• After the corpus grows. Pool sizes change, and guidance hardcoded to a count goes stale. The source study's recommendation (idea-factory#355) went stale exactly this way.
• After adding or removing tags. A tag query that was inert on the old corpus may now select a meaningful subset.

Prerequisites

Commands

sweep

Run match-voice + tighten over (article × arm) pairs, record register markers.

pixi run python3 tune_anchors.py sweep \
  --voice-dir ../writing-voice \
  --articles article-a.md article-b.md \
  --arms "tags~clipped" "role=venue-voice" "pre_ai=true" \
  [--n 24] [--model gemma4:12b] [--out ledger.yaml] [--dry-run] [--no-tighten]

--dry-run runs retrieval only (no model, no cost). It records which anchors would be selected per paragraph — enough to detect the GH-215 shape (wrong anchors selected, correct ones discarded) without spending compute.

Full mode runs drive.py then tighten.py per (article, arm), captures register markers and structural metrics from the tightened output. Requires Ollama.

--no-tighten skips the tighten step and measures the raw voice draft.

rank

Score arms on the register composite, emit a sorted table.

pixi run python3 tune_anchors.py rank --ledger ledger.yaml [--blind]

--blind hides arm labels, replacing them with 8-character hashes, and shuffles the output. Blindness matters: in the source study the operator twice guessed wrong about which sources were clipped.

Disagreements — an arm that ranks well on local metrics but poorly on the detector (or vice versa) — are flagged with a WARNING rather than averaged away.

verify

Scan top K with Pangram, record detector results.

pixi run python3 tune_anchors.py verify --ledger ledger.yaml --top 3 [--budget 10]

This is where the money goes, and it is deliberately last. Refuses to exceed --budget total scans. Records results back to the ledger so rank can surface disagreements on the next run.

Worked example

# 1. Dry-run: see what retrieval selects (free)
pixi run python3 tune_anchors.py sweep --dry-run \
  --voice-dir ../autogenic-systems/writing-voice \
  --articles posts/2026-07-distributed-scheduling.md \
  --arms "tags~clipped" "role=venue-voice" "tags~economics"

# 2. Full sweep: voice + tighten (requires Ollama)
pixi run python3 tune_anchors.py sweep \
  --voice-dir ../autogenic-systems/writing-voice \
  --articles posts/2026-07-distributed-scheduling.md \
  --arms "tags~clipped" "role=venue-voice" \
  --model gemma4:12b --out calibration.yaml

# 3. Rank: which arm produced the best register after tightening?
pixi run python3 tune_anchors.py rank --ledger calibration.yaml

# 4. Verify top 2 with Pangram (optional, costs 2-4 scans)
pixi run python3 tune_anchors.py verify --ledger calibration.yaml --top 2 --budget 6

# 5. Record the winner into the venue profile (GH-339)
pixi run python3 ../match-structure/scripts/venue_profile.py set-anchors \
  --venue newsletter --voice-dir ../autogenic-systems/writing-voice \
  --arm "tags~clipped" --composite 0.81 \
  --note "swept 1 article, gemma4:12b, verified top-2"

Recording the winner (writeback)

A sweep whose result lives only in a ledger gets re-guessed next quarter. When the repository carries venue profiles (writing-voice/venues/, see the writing-voice rule), record the winning arm into the profile it was swept for: set-anchors writes the arm as the profile's anchor_query and stamps provenance (source, date, composite, note), so the profile always carries the last calibrated arm rather than a hand-guessed one. Pass the winning arm expression exactly as rank printed it — set-anchors parses it with this skill's own parser.

The three findings this harness encodes

Pool size is a confound. A comparison of two tag queries with different pool sizes measures size and identity together. The --n flag samples arms to a common size; vary size only as its own arm.

Local metrics and the external detector can point opposite ways. A sweep cannot rank on either signal alone: it needs both, recorded separately, with disagreement surfaced rather than averaged away. That is why verify is a separate step that records to the ledger rather than a number folded into the composite.

Tightening is not optional in the production pipeline. Ranking on the raw voice draft over-penalizes arms whose AI-register markers are removable and under-rewards arms whose markers persist through tightening. The harness measures what the reader sees, not what the model produced.

Relationship to other skills

• match-voice — the rewrite engine this harness drives. sweep calls drive.py per trial.
• tighten-style — the AI-register removal step. sweep calls tighten.py on each voice draft before measuring.
• filter-tells — the register measurement this harness reads. rank scores on the same four-axis composite register_markers.py computes.
• match-structure — provides voice_anchors.py, the retrieval engine that sweep --dry-run calls directly.