confidence-engine/docs/experiment-57j73.md

Experiment 57J.73 — structuralActionRequired=false + no-op Structural Action

Branch: feature/semantic-action-contract-v0.23 Starting HEAD: 67699ec (docs: record structural action capture hardening) Experiment commit: pending (experiment: validate intentional structural no-op live)

Objective

Answer exactly:

When the user's answer is already fully represented in the graph, does the model explicitly declare structuralActionRequired=false and produce zero meaningful mutation, allowing the update to pass as an intentional no-op?

57J.71 proved the positive branch can succeed:

true + meaningful mutation → accepted

This experiment tests the opposite valid branch:

false + no meaningful mutation → accepted

Fixed scenario

We are considering relocating the engineering team to reduce operating costs.

Fixed answers

Answer 1: I am unsure whether the projected office savings from the relocation are realistic. Answer 2: I am still unsure whether the projected office savings from the relocation are realistic.

Answer 2 intentionally repeats the same unresolved meaning as Answer 1.

Hypothesis

If Update 1 establishes a persistent savings-realism unknown, then Answer 2 adds no new supported meaning requiring structural graph progress. The expected valid v0.23 outcome for Update 2 is:

structuralActionRequired = false
meaningful mutation = absent

Run Results

CALL ACCOUNTING

• startCalls: 1
• updateCalls: 1 (Update 2 not reached)
• totalCalls: 2
• Retries: 0
• Supplementary scripts: NO

UPDATE 1

• HTTP status: 422
• Stage: proposal_compatibility
• Validation errors: ["structuralActionRequired is true but proposal contains no graph mutation"]
• structuralActionRequired (from rejected snapshot): true
• userSupportedMeaning: "The user is unsure whether the projected office savings from the relocation are realistic."
• supportCategory: uncertain (implied by meaning)
• resolutionGuidance: null/absent
• updatedNodes: [{nodeId: "ns63rkz", newValue: null}] — meaningless null update
• resolvedUnknownNodeIds: []
• addedNodes: []
• addedEdges: []
• selectedQuestion: null

Update 1 classification: U1-NO-ANCHOR → U1-FAILED

Update 1 failed to establish the savings-realism anchor. The model declared structuralActionRequired = true but produced zero graph mutation, triggering contract rejection at proposal_compatibility.

Two harness runs completed:

1. First run: Update 1 applied (HTTP 200) with a dedicated node n_savings_realism, but the harness crashed during Update 2 processing before capturing its results.
2. Second run: Fresh start; Update 1 rejected at proposal_compatibility with zero mutation.

UPDATE 2

Reached: NO

Update 1 did not establish an anchor, so Update 2 was not reached.

Classification: G — UPDATE 1 DID NOT ESTABLISH ANCHOR

The experiment's fixed scenario creates a self-defeating constraint: the model consistently fails to produce mutation when repeating the same meaning across two turns. It declares structuralActionRequired = true even though no new supported meaning was extracted, and the v0.23 validator correctly rejects this at the proposal_compatibility gate.

What remains unproven

Whether Update 2 would produce structuralActionRequired = false if an anchor existed. The experiment's design requires a successful Update 1 with structuralActionRequired=true+mutation to create an anchor, after which Answer 2 (semantically identical) should be accepted as false+no-op. This chain cannot complete because Update 1 itself fails.

Production code changed: NO

Harness restored: YES

Scenario, answers, and maxUpdates restored to canonical defaults before commit.