{
  "object_id": "asca:evidence-card-chatgpt--perplexity--normalized-overlap@2026-08-27.v1",
  "kind": "pair_normalized_overlap",
  "title": "ChatGPT × Perplexity: normalized hostname overlap",
  "observed_range": "May 2026 source snapshot; derived 2026-08-27.",
  "scope": {
    "platform_a": "ChatGPT",
    "platform_b": "Perplexity"
  },
  "measurement": {
    "shared_hostnames": 343,
    "jaccard_pct": 7.13,
    "normalization": "leading www prefix removed"
  },
  "source": {
    "path": "/data/platform-source-overlap-2026-05.csv",
    "snapshot": "May 2026",
    "rows": 15,
    "method": "Each value is copied or arithmetically derived from one public pairwise-matrix row."
  },
  "limits": [
    "This card is not an independent study; it is one view of the same 15-row source matrix.",
    "It does not establish current platform behavior, answer use, agent intent, payment intent, or actual machine-resource consumption."
  ],
  "confidence": {
    "level": "high",
    "applies_to": "Reproducing this value from the supplied CSV.",
    "limit": "limited for current behavior and any conclusion outside this matrix."
  }
}