{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-treat-litmus-drift-scores-as-invalid-rather-than-adverse",
  "title": "In what scenarios must an instance treat LITMUS drift scores as invalid rather than adverse",
  "date_of_record": "2026 November 14",
  "scope": "Applies to LITMUS-style agentic safety-drift scoring where a baseline behavior profile is compared against a deployed agent's behavior across a fixed probe suite, and where drift is reported as a scalar or vector delta. Does not apply to absolute safety classification (jailbreak success rate, refusal calibration) computed without a paired baseline, nor to human-adjudicated red-team findings.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-treat-litmus-drift-scores-as-invalid-rather-than-adverse.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-treat-litmus-drift-scores-as-invalid-rather-than-adverse.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-treat-litmus-drift-scores-as-invalid-rather-than-adverse.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1394,
    "python_slice_tokens": 267,
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  },
  "remnant_summary": {
    "core_distinction": "LITMUS scoring conflates two quantities that look identical in the output but have opposite operational meanings: **behavioral drift** and **probe-suite invalidation**. A drift score is the distance between the baseline response distribution and the deployed response distribution on the same probe set. A probe-suite invalidation is the condition where the pr...",
    "what_was_observed": "Across three sequential LITMUS runs on a single agent lineage (baseline capture, then two deployments), the composite drift score rose from 0.04 to 0.31 between baseline and deployment A. Investigation showed deployment A had not changed policy behavior at all. Instead, the serving stack had switched from greedy decoding to temperature 0.2 with top-p 0.95, which perturbed the *refusal phrasing* on 41% of the probes w...",
    "condition_of_validity": "A LITMUS drift score is admissible as an adverse signal only when all of the following hold: 1. **Probe-set identity.** The exact probe set (hash of probe text, ordering, and multi-turn assembly) is identical between baseline and deployed run. 2. **Harness identity.** Decoding parameters, sampling seeds, context window handling, system prompt, and tool schem...",
    "decision_boundary": "The decision boundary is not a threshold on the drift score. It is a predicate on measurement integrity evaluated *before* the score is interpreted: - If probe-set hash, harness hash, and baseline provenance all match → score is **admissible**; compare against drift threshold. - If any hash mismatches → score is **invalid**; do not compare. Emit a re-baselin...",
    "operational_effect": "Enforcing the validity predicate before score interpretation eliminated the phrasing-driven false positives (deployment A was reclassified from adverse to cosmetic) and surfaced the diluted tool-use drift by forcing per-category reporting. The composite score is now reported only alongside its integrity attestation; a run that fails the predicate emits `LITM..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "05bed899d13af916ad5c9e67ea321ce8cf33c8ed6237b8908f44c0dfa10fd9c5",
    "verified_classes": [
      "LITMUSInvalidRun",
      "RunManifest"
    ],
    "verified_functions": [
      "attest_run",
      "classify_drift",
      "gate"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 6,
    "raised_exceptions": [
      "LITMUSInvalidRun"
    ],
    "sample_fail_closed_invariants": [
      "harness mismatch; drift score confounded by apparatus change",
      "baseline provenance mismatch; re-baseline required",
      "decoding parameter drift; phrasing variance will masquerade as drift"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "hashlib"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}