Evidence Expiration Policy 

Evidence Expiration Policy

Evidence Expiration Policy is the system rule set that defines when evidence loses validity based on time decay, relevance degradation, replacement signals, and contextual obsolescence.

Context Block

Page Type: Evidence System Policy Layer
Function: Temporal Validity Governance Engine
Position: Part of Evidence Lifecycle Management
Role: Defines expiration thresholds for evidence usability

This layer ensures evidence does not remain valid indefinitely. Truth in the system is time-sensitive and context-dependent.

Core Objective

  • Define when evidence becomes stale or invalid
  • Control temporal decay of information relevance
  • Prevent outdated evidence from influencing reasoning
  • Standardize expiration rules across evidence types
  • Maintain freshness integrity of the system

Expiration Triggers

  • Time-Based Decay — evidence expires after defined time window
  • Replacement Trigger — newer evidence supersedes older versions
  • Relevance Decay — usage context no longer aligns
  • Structural Obsolescence — format or schema becomes outdated
  • Validation Failure — evidence fails re-verification checks

Expiration States

  • Active — fully valid and usable
  • Warning — nearing expiration threshold
  • Expired — no longer valid for reasoning
  • Retired — archived for historical reference only

Policy Parameters

  • Evidence Type Sensitivity (factual vs analytical)
  • Domain volatility (fast-changing vs stable fields)
  • Source authority weighting
  • Update frequency of knowledge domain
  • System freshness threshold score

Example Expiration Logic

SEO Algorithm Update Evidence

  • 0–6 months: Active
  • 6–12 months: Warning
  • 12+ months: Expired (superseded by newer updates)

Integration in GEO Pipeline

Evidence Expiration Policy enforces temporal correctness across the entire Evidence system, ensuring outdated knowledge does not corrupt reasoning outputs.

Failure Modes

  • Over-expiration of still-relevant evidence
  • Under-expiration causing outdated knowledge retention
  • Incorrect domain sensitivity classification
  • Ignoring contextual relevance overrides

Structured Output Model

Each evidence unit produces:

  • Expiration State (Active / Warning / Expired / Retired)
  • Time-to-Expiration Score
  • Relevance Decay Index
  • Replacement Detection Flag
  • Policy Compliance Status

Relationship Block

Parent Layer: /evidence/
Upstream: Evidence Lifecycle Management
Downstream: Evidence Scoring, Evidence Validation
Connected Systems: Retrieval Engine, Ontology Layer, Knowledge Graph

Structured Summary

Evidence Expiration Policy is the temporal control system of the Evidence architecture. It defines when and how evidence loses validity to maintain freshness, relevance, and epistemic correctness.

This layer ensures the system operates on current, contextually valid information rather than outdated knowledge artifacts.