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

Concept ↔ Implementation Fitness Map

Updated: 2026-08-22 (TD-WP-0002-T07)

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	C1	world.py	E-001	td://self/actor-isolation	F-0003 — only observable when the scenario plants canaries.
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	C1	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	C1	— (T08)	E-001	—	(H-002)
C-classification	C1	— (T08)	E-001, E-003	—	Decision table is total on paper; unexercised.
C-crystallization	C1	— (T09)	E-002	—	(H-003)
C-intent-provenance	C1	provenance.py	E-003	td://self/intent-independence	Constrains provenance, not quality. Accepted residual.
C-lineage	C0	—	—	—	Parent pointer only in the spike.
C-energy	C0	energy.py, capture only	—	—	Dormant by decision. (H-005)
C-temperature	C0	—	—	—	Deferred. No implementation planned in TD-WP-0002.
C-confidence	C0	—	—	—	Deferred.
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. energy.py is the one to watch: it exists solely to capture events for a dormant hypothesis, and if T10 finds no use for the history it should be removed rather than kept out of sentiment.