{
  "id": "palimpsest-news:coverage-guard",
  "slug": "coverage-guard",
  "url": "https://palimpsest.info/news/coverage-guard/",
  "signal_id": "coverage-guard",
  "headline": "Coverage changes confound 0 current signal",
  "dek": "The guard withholds a censorship interpretation when movement can be explained by a changing measurement base.",
  "section": "command",
  "order": 3,
  "type": "methodology",
  "priority": "high",
  "status": "live",
  "published_at": "2026-08-24T15:55:45Z",
  "modified_at": "2026-08-24T15:55:45Z",
  "claim_fingerprint": "sha256:00ce2857f7b3d161951c22846e1b4ef3ffb18ed26b896aad05369cf445534aa3",
  "metric": {
    "label": "confounded signals",
    "value": 0,
    "unit": "count",
    "denominator": {
      "label": null,
      "value": null
    }
  },
  "claims": [
    {
      "type": "method",
      "statement": "The current coverage audit marks 0 signal as confounded by its measurement coverage."
    }
  ],
  "evidence": {
    "url": "https://palimpsest.info/readings/coverage-guard-latest.json",
    "input": {
      "filename": "coverage-guard-latest.json",
      "sha256": "04499879c26b00d5362bb5cb22fc8e4fbd3c4eed9c0d3d7d521466acf6765e78",
      "bytes": 4327
    },
    "source_timestamp": "2026-08-24T15:55:45Z"
  },
  "method": {
    "summary": "for each signal with a recorded sample size: robust (MAD) z of the metric and of its denominator, then least-squares metric ~ a + b*denominator over the reference readings and the latest residual scored against reference residuals. CONFIRMED when the departure survives conditioning (>= 0.5 of the raw z and >= 2); COVERAGE_CONFOUNDED when it does not; INCONCLUSIVE when the fit cannot support either call",
    "version": null
  },
  "limitations": [
    "A coverage-confounded signal is inconclusive about substantive change, not evidence that no change occurred."
  ],
  "related_signal_ids": [
    "board-alarm",
    "event-flags",
    "ddti"
  ]
}