{
  "schema": "weatherwatch.finding/v1",
  "finding_id": "weatherwatch.finding.observer-divergence.2026-08",
  "slug": "observer-divergence-2026-08",
  "status": "published",
  "published_month": "2026-08",
  "headline": "Jetstream observers disagree.",
  "claim": "Concurrent same-region public Jetstream observers reported substantially different post volumes over the same interval.",
  "result": {
    "headline_ratio": 1.611,
    "display_ratio": "1.61\u00d7",
    "same_observer_control_ratio": 1.0,
    "display_control_ratio": "1.000\u00d7",
    "comparison": "jetstream1.us-east / jetstream2.us-east"
  },
  "design": {
    "duration_seconds": 120.0,
    "concurrent": true,
    "same_region": "us-east",
    "metric": "app.bsky.feed.post events delivered",
    "observers": [
      {
        "endpoint": "jetstream1.us-east",
        "sockets": 1,
        "post_events": 7088,
        "relative_to_high": 1.0
      },
      {
        "endpoint": "jetstream2.us-east",
        "sockets": 2,
        "post_events_per_socket": [
          4400,
          4400
        ],
        "relative_to_high": 0.6207674943566591
      }
    ]
  },
  "implication": "An observed firehose volume may depend on observer choice; a study must disclose and condition on its observation source.",
  "limitations": [
    "This is an inter-observer comparison, not a coverage estimate.",
    "There is no canonical denominator in this experiment.",
    "The result does not establish which observer was more complete.",
    "Equal aggregate counts do not prove equal event sets.",
    "Weather Watch retained no raw events or event identities, so it cannot perform set inclusion or set equality analysis."
  ],
  "repository_receipts": [
    "M0-VERIFICATION-RESULTS.md",
    "docs/JETSTREAM-OBSERVER-DIVERGENCE.md",
    "measurements/instances2.json",
    "spike/m0_probe.py"
  ],
  "public_receipts": [
    "finding.json",
    "receipts/instances2.json"
  ]
}