# Model Error **Domain:** Modeling / Statistics / Governance **Doc Type:** Failure-Mode Node **Maturity:** Developed ## Definition **Model error** is consequential mismatch between a model and the system, process or subject it is used to represent. ## Sources of Error Error can arise from wrong structure, omitted variables, poor calibration, stale data, measurement bias, invalid transfer between contexts or use outside the model's intended purpose. ## Governing Variable Model error governs the difference between apparent and actual decision conditions. ## Relation to Governance An error becomes politically important when an [[wiki/Operational Representation|operational representation]] allocates access or changes the environment. [[wiki/Continuous Reconciliation|Continuous Reconciliation]] can amplify the problem if correction based on the wrong model generates new observations that appear to confirm it. ## Constitutional Question and Failure Modes Systems should expose uncertainty, intended use, provenance and evidence boundaries. The worst failure is not simply an inaccurate prediction but a model that becomes unappealable because its output is treated as the authoritative reality. ## Related Ontology [[wiki/Model Fidelity|Model Fidelity]] · [[wiki/Evidence Boundary|Evidence Boundary]] · [[wiki/Model-Subject Boundary|Model-Subject Boundary]] · [[wiki/Representational Due Process|Representational Due Process]]