{
  "handle": "Correlation",
  "data_schema": {
    "type": "object",
    "required": [
      "variable_a",
      "variable_b",
      "coefficient"
    ],
    "properties": {
      "variable_a": {
        "type": "string",
        "description": "First variable ID"
      },
      "variable_b": {
        "type": "string",
        "description": "Second variable ID"
      },
      "coefficient": {
        "type": "number",
        "minimum": -1,
        "maximum": 1,
        "description": "Normalized correlation coefficient [-1, 1] under the selected method"
      },
      "p_value": {
        "type": "number",
        "description": "Statistical significance of the correlation"
      },
      "sample_size": {
        "type": "integer",
        "description": "Number of observations"
      }
    }
  },
  "mechanism": "A normalized measure of statistical association between two {{variable}}s under a selected correlation method. The coefficient lies in [-1, 1] and is interpreted according to that method. Correlation alone neither establishes nor rules out {{causation}}, its direction, or an intervention effect.",
  "gloss": "Normalized statistical association; no causal conclusion by itself",
  "_meta": {
    "ring": 1,
    "tier": 1,
    "supersedes": [
      "sema:Correlation#mh:SHA-256:091fbf1f3baec2028bbd64c9d2ff335ef41d9ec6ec992e1967c5bca02c777625",
      "sema:Correlation#mh:SHA-256:3e6845523b8166fa55b82ef6ecd1ae129688fae1507fc6b4f92b9bc662936f42"
    ],
    "path": [
      "Infrastructure",
      "Data Structures"
    ]
  },
  "invariants": [
    "The coefficient lies in [-1, 1].",
    "The correlation alone establishes neither the presence nor absence of {{causation}}, its direction, nor an intervention effect, regardless of coefficient magnitude."
  ],
  "failure_modes": [
    "Causal overreach: the result alone is used to assert a causal relation, its absence or direction, or an intervention effect.",
    "Source ambiguity: direct causation, reverse causation, confounding, and selection can produce similar coefficients, which correlation alone cannot distinguish.",
    "Method blindness: dependence outside the selected method's sensitivity yields a weak coefficient that is read as independence."
  ],
  "sema_id": "sema:Correlation#mh:SHA-256:3bd8ecb518efc816c4c986e434afb9b2c3d3801b8099e008c15b70e305bd3043",
  "sema_ref": "Correlation#3bd8",
  "sema_stub": "3bd8",
  "dependencies": {
    "references": {
      "causation": "sema:Causation#mh:SHA-256:ed6cdeb5f2972a180d13c58e1b51957e7309cd78052a029a56e34dad9a8a6850",
      "variable": "sema:Variable#mh:SHA-256:5333c0009a269825753bf5470554844285c46920c32e3d46ed71403090224dc7"
    }
  },
  "sema_layer": "Infrastructure",
  "sema_category": "Data Structures",
  "used_by": {
    "references": {
      "DataMinimization": "sema:DataMinimization#mh:SHA-256:e8c8cd89b8e187d501000746c5216fef9ea41558a20fde07372881a2948994eb",
      "SomaticMarker": "sema:SomaticMarker#mh:SHA-256:25c9f71e623cfc2114e71c853ddea757abbfc319880ab654d2b875feec99973a"
    }
  }
}