confidence-engine/docs/experiment-60b30.md

Experiment 60B.30 — Uncertainty over whether... Proposition Coverage

Branch: feature/proposition-prefix-over-v0.32
Starting HEAD: 35a5efa80480eb00e69b1004f33e20330fe2434e
Date: 2026-08-14
Status: COMPLETE

Objective

Close the narrow live coverage gap exposed by 60B.29 by extending the existing bounded proposition-prefix normalization so:

Uncertainty over whether X...

enters the same whether ... proposition-extraction path already used for:

Whether X...
Unknown whether X...
Uncertain whether X...
Uncertainty about whether X...
Uncertainty regarding whether X...

60B.29 Live Gap

60B.29 preserved the full reasoning chain live but surfaced a new bounded synonym form in the node description:

Uncertainty over whether the prospective enterprise customer will sign if we launch this year, because their contract accounts for approximately £700,000 of the expected first-year revenue and could materially flip the net-value comparison.

Because uncertainty over was not part of the existing normalization boundary, deterministic formulation did not expose:

whether the prospective enterprise customer will sign if we launch this year

to the established evidence-framed proposition path.

Exact Normalization Added

Production change was limited to lib/graph/question-formulator.js.

Inside extractMeaning(), the description-start normalization used before the existing ^whether proposition check now also strips:

uncertainty over

case-insensitively.

This means the following bounded forms are now equivalent for proposition extraction:

Whether X...
Unknown whether X...
Uncertain whether X...
Uncertainty about whether X...
Uncertainty regarding whether X...
Uncertainty over whether X...

Each now exposes:

whether X

before the existing rationale stripping and evidence framing run.

Exact 60B.29 Deterministic Regression

For:

label:
Prospective enterprise customer signing status

description:
Uncertainty over whether the prospective enterprise customer will sign if we launch this year, because their contract accounts for approximately £700,000 of the expected first-year revenue and could materially flip the net-value comparison.

the deterministic final question is now:

What evidence would clarify whether the prospective enterprise customer will sign if we launch this year?

The final question excludes:

• £700,000
• expected first-year revenue
• materially flip
• because their contract

and the source description remains unchanged.

Focused Verification

Run exactly as bounded:

npx vitest run tests/graph/question-formulator.test.js

Result:

PASS — 39/39 tests

Focused coverage confirms:

• exact 60B.29 regression passes
• Uncertainty over whether... without rationale uses evidence framing
• previously-supported prefixes remain unchanged
• direct interrogatives remain unchanged
• nominal non-whether behaviour remains unchanged
• source description remains intact

Preserved Existing Paths

This change did not:

• redesign question formulation
• broaden parsing beyond one explicit uncertainty synonym
• add domain-specific wording
• change decision-family routing
• change question-target selection
• change graph structure, materiality, schema, provider, or harness behaviour

What Remains Unproven

Deterministic coverage for Uncertainty over whether... is now proven, but the exact full live 60B.29 rerun on this branch remains to be executed.