Boundary Coherence Model (BCM): A Diagnostic Framework for Measuring Institutional Definitional Drift

The Boundary Coherence Model (BCM) is a fully specified, constraint-driven methodological framework for measuring the coherence between institutional definitions and material outcomes. The framework operationalizes institutional analysis through a structured evidence hierarchy, a formal measurement model, and a reproducible audit protocol designed to minimize interpretive drift and enforce epistemic discipline. BCM defines coherence as the degree to which formal definitions, policies, or stated mandates remain coupled to observable outcomes under audit conditions. The model distinguishes three evidence tiers—T1 (material outcomes), T2 (documented artifacts), and T3 (discourse)—and enforces strict constraints on claim formation, such that findings cannot exceed the evidentiary support available. A hierarchical claim system (Signal through Certified) governs permissible conclusions, preventing overstatement and ensuring transparency of uncertainty. At its core, BCM introduces the Coherence Index Score (CIS), a bounded scalar derived from a structured attribute system that evaluates institutional behavior across multiple dimensions of coherence. The framework includes a suite of supporting metrics (e.g., symmetry decay, boundary drift, mask–material divergence, entropy, and reversion index) designed to detect and classify structural drift. All metrics are explicitly defined, bounded, and subject to sensitivity analysis. To address known methodological vulnerabilities in complex evaluative systems, BCM incorporates: Multiverse (specification-curve) analysis and variance decomposition to prevent parameter selection bias Measurement invariance protocols for cross-domain calibration Multi-trait multi-method (MTMM) analysis to detect and control construct redundancy A structured Indeterminate classification system with signal detection controls to manage uncertainty Adversarial dual-coder protocols with defined inter-rater reliability (IRR) thresholds The framework is organized as a complete audit system, including: A 27-attribute coding manual with explicit boundary conditions and evidence requirements A tiered failure-gate system for structural classification A staged deployment architecture (Stage 0–3) that links operational capability to claim ceilings A full audit workflow specifying data collection, coding, adjudication, and output generation BCM also defines a strict separation between institutional analysis and individual-scale application (referred to as SOS), enforcing a firewall to prevent cross-layer contamination of findings. This publication presents the BCM as a complete methodological specification. The system is fully defined at the architectural and procedural levels and is designed to be falsifiable, replicable, and extensible. At the time of publication, the framework is pre-validation: empirical calibration, inter-rater reliability studies, and prospective validation remain to be conducted. The intended contribution of BCM is not to provide normative judgment or measure institutional virtue, but to offer a structured, evidence-bound instrument for detecting and analyzing definitional drift in complex systems.