test-driver/research/concepts/fitness-map.md

Concept ↔ Implementation Fitness Map

Updated: 2026-08-23 (TD-WP-0002-T10)

Traces each important concept to the implementation, experiment and evidence that support it. Unsupported entries are the point of this map — a concept with no implementation and no evidence is not a gap to be embarrassed about, it is the current honest state, and hiding it defeats the map's purpose.

Support levels follow TestDriverImprovementLoop.md §13: C0 Idea · C1 Hypothesis · C2 Experimentally Supported · C3 Practically Validated · C4 Architectural Invariant

Current state

C-semantic-action is the first concept to reach C2: it has an experiment behind it (the T07 two-arm comparison), and that experiment narrowed the claim rather than confirming it. Everything else still rests on unit tests.

The deterministic kernel exists (T04) and its guarantees are covered by unit tests. Levels do not move for those. A passing unit test is not an experiment: it shows the code does what its author intended, not that the concept holds under the mutations it claims to survive. Levels rise when E-001/E-002/E-003 produce evidence, not before. The implementation column below moves; the level column does not. The initial classifications in §13 of the Improvement Loop (Actor Isolation C2, Independent Oracles C2) are corrected downward here: they were aspirational, not evidenced.

Concept	Level	Implementation	Experiment	Evidence	Open question
C-use-case	C1	intent.py	—	—	Is a use case expressible without leaking mechanics?
C-actor-isolation	C2	world.py, runner.py	E-001	td://self/actor-isolation, examined every run	F-0003 resolved — automatic canaries; observable on every scenario.
C-semantic-action	C2	actions.py, agentic.py	E-001 (partial)	T07 arm comparison	F-0005 — supported only where stable identifiers are absent. Narrower than the concept model claims.
C-oracle-independence	C2	runner.py, oracles.py	E-001, E-003	—	Independence of components ≠ independence of belief. (H-004)
C-evidence-pack	C1	evidence.py	—	td://self/evidence-reproducibility	Verdicts are reproducible from S3 alone, on passing and failing runs.
C-observation-channel	C1	lab/app.py	—	—	D-07 — required of every system under test. Adoption cost unknown.
C-adaptation	C2	classification.py, agentic.py	E-001	T08 matrix	11/12 mechanical absorbed without a human.
C-classification	C2	classification.py	E-001, E-003	T08 matrix, FAR 0/7	F-0006 — cannot infer SEMANTIC vs DEFECT; collapses to one escalating outcome.
C-crystallization	C2	crystallization.py	E-002	T09 agreement matrix	Fidelity supported; F-0007 — the economic case is unmeasurable with a token-free runtime.
C-intent-provenance	C1	provenance.py	E-003	td://self/intent-independence	Constrains provenance, not quality. Accepted residual.
C-lineage	C1	scenario.py, generated headers	E-002	generated module docstring	Parent pointer plus provenance in the artefact; no graph.
C-energy	C0	energy.py, capture only	—	none	Dormant. Gated: if the next workplan ends with no decision having used the history, remove.
C-temperature	C0 — under review	—	—	none	F-0008 — crystallization was built without it; measured stability did the work. Gated for removal.
C-confidence	C0	—	—	none	Declared, unimplemented, never consulted. Same position as C-temperature without a built alternative.
C-campaign	C0	—	—	—	Deferred.
C-metabolism	C0	—	—	—	Deferred. Depends on C-energy.
C-retirement	C0	—	—	—	Deferred. Depends on C-energy.
C-security-mutation	C1	lab/mutations.py	E-003	lab/GROUND-TRUTH.md	Catalogue is hand-written; no derivation mechanism from use cases yet.

Orphan check

Conceptual orphans — concepts with no planned implementation in TD-WP-0002: C-temperature, C-confidence, C-campaign, C-metabolism, C-retirement.

All five are deferred by explicit decision, not oversight. They are the group most at risk of being built because they are easy and satisfying, and never validated. They are revisited at T10, where the question is not "when do we build these" but "does the evidence justify keeping them in the model at all".

Implementation orphans — none. Every module in src/testdriver/ traces to a concept above.

Removed at T10 (compression pass — see the gate review § 3): Verdict.SUSPICIOUS, Step.expect_refusal, ActorIsolationError, World.seed, EvidencePack.latest(), Trajectory.method. Each was declared and never used; SUSPICIOUS was additionally a verdict no oracle could emit.

Gated for removal: C-temperature (F-0008) and energy.py. Both survive the current review on the strength of being cheap, not of being used. If the next workplan closes without a decision consulting either, they go.