🔴 Mutation Blast Radius
Mutation Blast Radius is the extent to which a proposed semantic or structural change propagates across dependent anchors within the Semantic Surface Area.
The Danger of Deep Dependencies
Even nominal changes (e.g., renaming a core term) may exhibit high MBR when the term functions as a semantic hub. In highly interconnected institutional systems, a simple revision can unintentionally alter the meaning of policies, rules, or governance constraints downstream.
Governing the Radius
High-MBR environments require structured containment. This includes:
- Pre-mutation reference inventory
- Criteria articulation
- Backward compatibility evaluation
- Authority validation
- Structured mutation containers
Mutation Blast Radius and Audit Frequency
Blast radius isn't only assessed before a change — it directly determines how often a piece of reasoning gets re-checked afterward. A PIFR's Mutation Blast Radius is what sets its TTL: the more a PIFR is relied on, the shorter its time-to-live before the next mandatory audit, not the longer. See Audit & Repair for the full mechanism — high blast radius earns more scrutiny, never less.
Mutation Blast Radius is what the Coherence half of Navigational Coherence has to protect: the shared structure a change could unknowingly break for everyone who depends on it.
Part of the PKOS Lexicon.