Reach-assessment
Type: kb/types/definition.md · Tags: foundations, computational-model, self-improving-systems
Reach-assessment is the capability of an evaluation process to judge whether a candidate commitment's claimed explanatory-reach is genuine rather than adaptive fit presented as explanation. It evaluates the content of the claim: whether the proposed mechanism or invariant supports the generality claimed. Checking that a new case matches the commitment's stated condition checks only the condition, not whether that condition names the real boundary.
For example, retaining “route prompts under 500 tokens to a cheaper model” after several successes does not establish that length explains task difficulty. Reach-assessment must distinguish that mechanism from a correlation in the fitting cases, such as by varying complexity while holding length fixed.
Scope
The assessment route must match the representational form carrying the commitment:
- Natural-language commitments require semantic judgment of their mechanism, alternatives, scope, and observed fit, such as the four-part explanatory-reach test.
- Symbolic commitments can be assessed through intervention, invariance, or proof obligations when the relevant causal structure or domain has been formalized. The developed boundary is formal symbolic systems assess explanatory-reach only through causal and proof obligations.
- Distributed-parametric commitments can be assessed through action-conditioned predictions tested over the interventions or shifts the commitment claims to cover. The developed route is world models assess explanatory-reach through action-conditioned prediction.
Mixed artifacts may compose these routes, but an assessment of one form does not automatically warrant the others. Proof reaches only across its axiomatized domain; observed predictive fit reaches only across the tested shift class.
Reflectivity supplies addressability, not this judgment. A reflective process may represent, match, reject, or rescope a commitment without being able to tell whether its stated scope is honest.
Exclusions
- Reach-assessment is not boundary matching, metadata checking, confidence, or the structural capacity to rewrite a commitment.
- Empirical success on the fitting cases does not establish the mechanism or its reach beyond them.
- Causal vocabulary, a proof engine, or a learned world model does not by itself supply reach-assessment. The evaluation process must exercise the relevant causal, proof, intervention, or shift test.
- Observational causal discovery is not assumption-free; its warrant remains conditional on its discovery assumptions.
Provenance and open boundary
The causal, proof, and predictive-world-model routes are established external machinery. Commonplace's contribution is to group them by the role they play when an improvement pathway evaluates a retained commitment. The natural-language route remains unexplained: LLM-mediated evaluators appear able to judge prose generalizations with some reliability, but this definition names that missing capability rather than supplying a theory of it.
The hyphenated compound reach-assessment carries this technical sense, and explanatory-reach names the property it judges. Bare reach remains ordinary English. The oracle-side limit is oracle domain and the generator-side limit is search range.
Misuse Cases
- Assuming that a reflective system has reach-assessment because it can revise a stored scope statement.
- Treating a passing test suite or accurate predictor as evidence of reach without testing the claimed mechanism, intervention, or shift boundary.
- Citing this definition to claim that reach-assessment is unique to LLMs; causal inference and proof provide older formal routes.
Relevant Notes:
- Reflective system — contrasts: supplies the structural capacity to represent and rewrite scope; reach-assessment is the judgment that capacity does not supply
- Representational form — grounds: the form carrying the commitment determines which assessment route is available
- Formal symbolic systems assess explanatory-reach only through causal and proof obligations — extends: develops the symbolic causal and proof routes and their formalization boundary
- World models assess explanatory-reach through action-conditioned prediction — extends: develops the distributed-parametric route and its shift boundary
- First-principles reasoning selects for explanatory-reach over adaptive fit — grounds: supplies the four-part negative test for natural-language commitments
- Abstract an experience into a lesson only when you can state where the lesson stops — grounds: identifies boundary selection as judgment rather than mechanical derivation
- Theory-mediated learning may improve sample efficiency under structured shifts — extends: makes reach-assessment the load-bearing condition of the proposed sample-efficiency payoff
Derived into:
- Formal symbolic systems assess explanatory-reach only through causal and proof obligations — the causal and proof routes worked out from this definition's representational-form split
- World models assess explanatory-reach through action-conditioned prediction — the distributed-parametric route worked out from this definition's representational-form split