{
  "schema": "vedokrok.public-item.v1",
  "release_id": "MHC-RPUB-20260920-75ad787a",
  "url": "/knowledge/audit-the-reference-class-before-trusting-its-base-rate",
  "id": "MHC-D-RESEARCH-0403",
  "version": "0.1.0",
  "title": "Audit the reference class before trusting its base rate",
  "summary": "A base rate is only as relevant as the cases allowed into its denominator.",
  "kind": "question",
  "body": "Inspect the class boundary before using its distribution. Ask which factors genuinely determine comparability, whether selection excluded inconvenient failures, whether the measurement definitions match, and whether structural changes make old cases less relevant. If different reasonable classes give different answers, show that sensitivity.",
  "limits": [
    "No reference class is perfectly homogeneous; the goal is a useful outside view with visible limitations, not a claim of exact exchangeability."
  ],
  "topics": [
    "union-decision-analysis-calibration"
  ],
  "intents": [],
  "source_ids": [
    "RS-E9B25C78E7287B34"
  ],
  "evidence": [
    {
      "claim": "Reference class forecasting uses outcomes from comparable past projects as an outside view, but recent review work highlights unresolved issues around reference-class selection and applicability.",
      "source_id": "RS-E9B25C78E7287B34",
      "role": "supports",
      "note": "A badly chosen class can give a confident but irrelevant base rate.",
      "locator": "Systematic literature review and limitations"
    }
  ],
  "use_when": [
    "A reference-class forecast produces a compelling percentile or average and the class itself has not been challenged."
  ],
  "avoid_when": [
    "No reference class is perfectly homogeneous; the goal is a useful outside view with visible limitations, not a claim of exact exchangeability."
  ],
  "example": "A 'similar SAP migration' class may become misleading if it mixes greenfield programs with small remediation runs.",
  "check": "The forecast includes a defensible class definition and at least one noted limitation or alternate-class sensitivity.",
  "question": "What rule put a past case inside or outside the class? · Were failed or cancelled cases captured? · Are duration, cost and completion defined the same way? · Has technology or process changed enough to weaken comparability? · Would another defensible class materially change the forecast?",
  "sources": [
    {
      "id": "RS-E9B25C78E7287B34",
      "title": "Reference class forecasting: promises, problems, and a research agenda moving forward",
      "url": "https://www.tandfonline.com/doi/full/10.1080/09537287.2025.2578708"
    }
  ],
  "relations": [],
  "collections": [
    {
      "id": "RC-3EA4A5EF5790DD81",
      "title": "Model the decision before buying more certainty",
      "url": "/collections/model-the-decision-before-buying-more-certainty"
    }
  ]
}