| How should a problem boundary remain useful and revisable? | Treat framing as a contextual selection of what matters, compare materially different cuts, state exclusions, and revise the boundary when new evidence changes the receiving use. | A fixed sponsor scope is the serious default; an unbounded whole-situation map is the opposite default. | The first suppresses consequential exclusions and the second cannot stop. Adapt: PSD.4:4.1–4.4 and 4.6 require decision-bearing dimensions, material exclusions, proportionate challenges, and the scope reason needed by the receiving use. | Kelly and Gero’s 2022 framing review, Litster, Cardoso, and Hurst’s 2024 mapping study, and Nickel, Hurst, and Duimering’s 2024 contextual trade-off study support explicit framing, externalized change, and contextual trade-offs. They establish neither one framing ontology, universal Method, shared frame, fixed boundary, prevalence, causality, nor superiority. | Reopen if later field evidence changes the best-known boundary practice or if new contextual evidence changes an included or excluded dimension. |
| When does a receiving use need exact contextual scope membership? | Keep ordinary inquiry cuts in plain language; use current A.2.6 only when the receiving use must decide whether one exact U.ContextSlice belongs to one declared U.Scope. | Treating every diagram box or topic perimeter as a declared exact scope is the serious default. | It substitutes apparent precision for boundary judgement and can hide unavailable evaluation. Adopt: PSD.4:4.5 distinguishes true, false, and unknown evaluation results and routes extension changes to the direct pattern. | Current A.2.6 supplies exact contextual membership, extension change, and refit discipline. Its applicability axis is independent of C.2.3 formality. It does not judge which participants, concerns, formulations, intervention families, or exclusions make a PSM boundary usable. Direct engineering, legal, safety, ethical, and governance practices retain their own boundaries and thresholds. | Reopen if the direct scope pattern gains the complete problem-boundary judgement at equal or lower effort, or if a relied-upon scope or membership result changes. |