053-Retire distillation without a successor term

Type: ../types/adr.md · Status: accepted

Status: accepted Date: 2026-07-17

Context

Distillation was a load-bearing vocabulary term — in the AGENTS.md vocabulary, a definition note, a tag in learning-theory's covered_by, note titles, and the Distilled into: link label. A corpus audit (2026-07-17, recorded in kb/work/theory-methodology-derivation/distillation-usage-audit.md) classified 464 occurrences and found the word covering operations with opposite maintenance semantics: entailment-preserving reshaping (methodology → skill; the output is re-derivable from the retained source) and evidence-to-rule generalization (traces → preference rule; the output must earn authority through testing). The definition note's own instance list spanned the boundary, and the KB's most theoretically load-bearing "distill" usage — the trace→rule ladder — was on the ampliative side. Because the word did not mark which control regime governed an artifact, use-shaped artifacts could borrow the recomputable-copy maintenance story without holding its checkability.

Two theory results shaped the remedy. Vocabulary collisions are prevented at write time, not resolved at read time: prose gives an unqualified technical sense no reliable namespace, co-loaded notes merge colliding senses silently, and a definition note binds too weakly to prevent drift — the distillation definition existed throughout the drift it failed to stop. And a minimality constraint: a technical term that is also a common English word taxes every future occurrence with a which-sense resolution, so a word earns a definition only when its operational consequences cannot be carried by plain prose with a citation. Applied strictly, a successor term derivation fails that bar — ordinary "derive" is close enough, and the strong sense can cite its theory directly.

Decision

Retire distillation as KB vocabulary with no successor technical term.

• "Derive" stays ordinary English. No definition note, no vocabulary entry. A passage that needs the strong sense — entailment-preserving reshaping with matching, fallback, and cache/staleness semantics — cites the theory's home: the two-layer execution system note, which states those maintenance regimes as citable claims.
• The link grammar carries the boundary. derived-from / Derived into: asserts the artifact adds no substantive claims beyond its source and receives recomputable-copy or managed-staleness maintenance; abstracted-from / Abstracted into: asserts the claims exceed the instances and authority is earned by testing. Semantics are specified in link-vocabulary.md. An entangled artifact is classified by its dominant regime as an explicit, falsifiable bet.
• Ampliative traffic routes to the discovery lifecycle. The coined compound discovery lifecycle is the technical term for staged ampliative acceptance; traffic enters at its conjecture phase and never inherits accepted status from the sentence that states it. Bare "discovery" is ordinary English — completed by retitling the insight note to conjecture is seeing the particular as an instance of the general, which removed the last title-level capture of the bare word.
• Distillation survives only in external systems' own command names, the machine-learning knowledge-distillation sense inside captured sources, and historical ADR text.

Implemented worked-case-first, per the wave plan in kb/work/theory-methodology-derivation/migration-plan.md: the receiving surfaces were promoted first (structure note, label semantics, lifecycle definition — all ten audit hard cases classifying cleanly against them), then the entangled usages were split (the trace→rule ladder renamed to abstraction vocabulary, distillation-is-transformation-not-selection retired, the tradeoff/lineage/rewrite trio retitled, ~16 mislabeled lineage edges flipped to abstracted-from), with the affected notes taken through full review-gate sweeps.

Consequences

• Easier: an artifact's maintenance regime is readable off its lineage label instead of inferred from an overloaded word; the incoming technical term is a greppable multi-word coinage, so the write-time uniqueness check is a lexical search rather than the multi-agent semantic classification the 464-hit audit required; the derived/abstracted boundary is policed by labels and review gates, which prose demonstrably could not do.
• Harder: the KB's most common composite operation — consumer-directed selection plus reshaping — no longer has a one-word name and must be described in plain language with a citation where the strong sense matters. The resonance with ML knowledge distillation is lost deliberately: that sense is statistical fitting, and the borrowed intuition sat on the wrong side of the exact boundary the KB sense needed to hold. Amended by ADR 054: this gap proved real, not hypothetical — writers filled it with unauthorized ad-hoc synonyms ("condense," "Extraction") inside the same migration that retired distillation for exactly this failure mode. ADR 054 names the operation adapted-from/operationalized-from; this decision's other three bullets are unchanged.
• Remaining churn, tracked not blocking: the mechanical rewording of the remaining derivation/selection-shaped instances; the META surfaces — the AGENTS.md vocabulary entry, deletion of kb/notes/definitions/distillation.md with its salvage map (28 inbound links, including the undefined-terms gate's worked example), retirement of the distillation tag from learning-theory's covered_by, the remaining distill* filenames, and this collection's own residue (ADR 011's hardcoded "directed context compression" gloss and the review-gate examples citing it). The kb/agent-memory-systems type-spec's Distilled form: field migrates on its own schedule.
• Risk: the control trap can recur under any future attractive label. The guard is the promoted invariant — load-bearing senses ride on schema positions, rare compounds, or link-required clausal binding, never on capturing a common word — and the label semantics that force every lineage edge to declare its regime.