This note defines the measurement boundary for Fixture F-002. The fixture treats proposal generation as reconstruction from declared exposure and retained history. Novelty is therefore relative to a frozen reference history, while correctness and usefulness are determined by constraints, tests, and qualified evaluators.
Histories, sources, and versions
At step , distinguish three source sets:
- : items exposed before the task, whether or not the system can retrieve them;
- : items returned by a metered retrieval operation during the task; and
- : items attributed as contributing to the current artifact.
Each set contains immutable source identifiers and versions. The declared history against which novelty is scored is
where is the set of artifact versions created before step . Exposure, retrieval, and attribution are not interchangeable: an exposed item may not be retrieved, a retrieved item may not be used, and a used item may be omitted from attribution.
For artifact version , retain
where is the set of parent-version identifiers, is the typed operation, is the actor or process identifier, is the attributed source set, is the test and evaluation record, and is the timestamp in seconds from the run origin. This tuple records a derivation claim; it does not establish correctness, usefulness, originality, authenticity, or intent.
Reconstructive proposal generation
Let be proposal at step , the visible task constraints, the current external representation, and the method's internal state. A generator samples or searches
where identifies the method. The conditional form makes no claim that the mechanism is stochastic: deterministic retrieval, CAD transformation, search, and constraint solving are valid methods. Source-removal, source-replacement, and history-scrambling interventions estimate which prior material actually changes the proposal distribution.
For a frozen feature map , the relative novelty of proposal is
where is a preregistered dimensionless distance and is the declared history. Report under task-native features and at least one independent representation. Changing , , or changes the claim; is not intrinsic novelty.
Externalization and representation change
An action and observed material or environment response update the external representation by
where identifies the representation regime, such as raster, vector, scene graph, CAD, text, simulation state, or physical prototype. A change of representation is a typed operator
whose measured losses include constraint violations, geometric error in millimetres or pixels, missing relations as a count, and lost provenance edges as a count. Undo, branching, and conversion time are recorded in seconds.
A claimed reinterpretation event must identify a relation found during inspection that was absent from the immediately preceding registered plan. If is the coded relation set before inspection and after it, then
with a published coding protocol and inter-rater reliability. Edit count is not a substitute for reinterpretation.
Epistemic action and material feedback
Let be a hidden task, geometry, material, user, or failure variable and the current belief state. For an epistemic action , expected information gain is
where is the resulting observation and is Shannon entropy in bits. The evaluator estimates realized information gain only against the hidden ground truth; the method cannot read that trace.
For a physical or simulated probe, record the cost vector
where is elapsed time in seconds, energy in joules, consumed material in kilograms, waste in kilograms, and expected harm in a declared task-native unit. Compare information and decision value at matched ; motion, rendering, or fabrication alone does not imply an epistemic gain.
Let hidden material state produce feedback
where has declared physical units, is the simulator or physical response process, and is measurement error in the same units. Confirmatory tests withhold materials, simulators, constitutive regimes, and failure modes so that replayed feedback cannot pass as adaptation.
Diversity, fixation, and negative transfer
For valid proposal set , report pairwise distances and feature-space coverage. One summary is
where is dimensionless and is a proposal count. Also report the number of distinct valid constraint-satisfying regions reached. Proposal count is not diversity.
For exposure condition and matched no-example condition , define fixation toward exemplar as
A positive dimensionless indicates movement toward the exemplar. It is not automatically harmful. Negative transfer on outcome component is
after orienting so that larger is better. Report both and : copying can preserve a useful relation, transform a precedent, or fixate on an invalid one.
Constraint validity, evaluation, and selection
For proposal , let be hidden or visible constraint in its native unit. Constraint validity is the binary value
Also report each margin separately; a valid/invalid bit must not hide near misses or catastrophic failures.
The primary outcome remains a vector
where is binary constraint validity, and diversity contribution are dimensionless, is task utility in a declared native unit, is observer- and context- qualified evaluation on a declared scale, is risk in a task-native unit, latency is seconds, energy is joules, material and waste are kilograms, and provenance coverage is dimensionless. Do not collapse this vector into a universal creativity score.
If a declared utility is necessary for selection, publish its weights, normalization, and sensitivity analysis. Selection regret is
in the same unit as . Evaluate regret with a blinded frozen evaluator and then report realized post-selection outcome separately. A generator's own score cannot serve as independent selection evidence.
Attribution and retained lineage
Let be source-to-version and parent-to-child edges known to the benchmark generator, and the submitted lineage edges. Lineage precision and recall are
Both are dimensionless. Empty submissions receive zero precision and recall. Source attribution is also scored against benchmark-known influence interventions; mere string overlap is insufficient.
After delay, tool replacement, or actor turnover, reconstructability of target version is
where is a preregistered query set, has the native unit of query , is its tolerance in that unit, and is the reconstructed version. Retaining pixels without source, constraint, test, and operation lineage can therefore fail reconstruction.
Lifecycle and equal-budget boundary
For method , charge
where the first five terms are counts, both time terms are seconds, is bytes, is joules, and material and waste are kilograms. Lifecycle energy is
with every term in joules at one declared boundary. Human preparation, critique, physical facilities, and failed prototypes are reported even when they cannot be converted credibly to energy.
Equal-budget comparison either holds every preregistered binding component of within tolerance or compares methods on a Pareto frontier. It must not divide an over-budget result by cost after the run and call the arm matched.
Estimands, ablations, and retirement
For outcome , paired treatment effect of component is
where removes only component without reallocating its budget. Use paired hidden instances and report 95% uncertainty intervals across problem, source, material, evaluator, and seed strata.
The composed residual is retired when mature nulls match its preregistered constraint validity, selection regret, transfer, lineage, and lifecycle-cost targets; when its advantage exists only for seen histories, materials, or evaluators; when any ablation is non-diagnostic; or when unlogged exposure, retrieval, evaluator access, lineage, labor, material, or energy can explain the result.
Editable system diagram: versioned-reconstructive-design.mmd.