confidence-engine/docs/experiment-60b11.md

Experiment 60B.11 — Prerequisite-aware preferred question targeting

Branch: feature/question-target-alignment-v0.27
Starting HEAD: 854c3aa
Date: 2026-08-13
Status: Complete

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Why 60B.9's broad honour-rule was too wide

The partial implementation inherited from 60B.9/60B.11 was already trying to preserve a model-selected node, but the broad idea behind the earlier change was still too permissive:

if model-selected node is valid and unresolved,
preserve it

That rule is too broad because it treats these two cases as equivalent when they are not:

1. a same-proposal-added material unknown that is ready to investigate now
2. a same-proposal-added downstream unknown that still depends on another unresolved same-turn unknown

The pricing regression proves the difference matters:

n_pricing depends_on n_commercial_value

Preserving n_pricing there would invert prerequisite-first investigation order.

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Winning rule implemented in production

The production boundary remains narrow and unchanged outside final target selection:

Prefer the model-selected target only when ALL are true:

1. proposal.selectedQuestion.nodeId exists
2. that node was added in this proposal
3. it is still a selectable unresolved unknown after mutation
4. it has NO unresolved same-proposal-added unknown prerequisite via depends_on

If any condition fails, the engine falls back to the existing deterministic selector unchanged.

Final wording still comes from the existing deterministic question formulator.

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Exact production boundary

Implemented only in the existing final-question selection path inside:

lib/graph/apply-proposal.js

No changes were made to:

• schema
• validator contract
• selection scoring weights
• question templates
• provider integration
• harness
• materiality rule semantics

No new dependencies were added.

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Prerequisite definition used

Only this direct same-proposal relationship blocks preference:

target --depends_on--> unresolved same-proposal-added unknown

The implementation checks direct dependsOn references and direct depends_on edges only.

These do not block preference:

• may_cause
• affects
• causes
• supports
• measures
• contained_in
• any other non-depends_on relationship

No transitive prerequisite planning was added.

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Pricing regression preservation

The established regression remains intact:

model-selected: n_pricing
prerequisite:  n_commercial_value
final selected node: n_commercial_value

This remains protected because n_pricing has an unresolved same-proposal-added depends_on prerequisite, so the preferred-target path is rejected and deterministic selection proceeds unchanged.

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Focused test results

60B.11 block

Command:

npx vitest run tests/graph/apply-proposal.test.js -t "60B.11"

Result:

PASS — 10/10 tests

Covered:

• same-proposal selected target with no prerequisite is preferred
• same-proposal selected target with same-turn depends_on prerequisite is blocked
• pricing regression preserved
• pre-existing model target not auto-preferred
• invalid / contradicted / missing-target fallback behaviour
• deterministic wording remains authoritative
• non-prerequisite edge types do not block preference

Focused suites

Command:

npx vitest run tests/graph/apply-proposal.test.js tests/graph/prompt-builder.test.js

Result:

PASS — 174/174 tests

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Prompt boundary

Only the selectedQuestion guidance was clarified in the existing prompt text. The prompt now states, in bounded terms, that the engine:

• validates the model's candidate
• retains deterministic prerequisite ordering
• favours a selected same-proposal node only when no unresolved same-proposal depends_on prerequisite blocks it
• preserves deterministic fallback selection and deterministic formulation authority

It does not claim unconditional model authority.

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What remains unproven until live regression

The bounded implementation is covered by deterministic tests, but one thing remains unproven in live behaviour:

the exact 60B.6 live continuation case,
where the model selects the newly exposed client-retention factor
and the final selected target preserves that same ready material unknown

That requires a live regression run against the exact live fixture path, which was intentionally out of scope here.