id: decision-tree
name:
  ja: "デシジョンツリー（期待値選択）"
  en: "Decision Tree (Expected Value)"
purpose:
  ja: "選択肢ごとの確率分岐と結果価値から期待値を算出し、推奨選択肢とその根拠経路を示す"
  en: "Probability branches and outcome values per option, resolved into an expected value, with the recommended option and the path that justifies it"
# A5 の裁定で draft として移設し、2026-09-04 に型ごとの承認を取って公開した。
status: published
# 索引カードの図版。pnpm layout:render が原本から描く。
still: ./still.png
category: decision
catalogOrder: 180
jobs:
  - compare-choose
  - prioritize-diagnose
useCases:
  - comparison
layoutKinds:
  - tree
tags: [decision-tree, probability, expected-value, scenario]
whenToUse:
  - ja: "不確実な選択肢を期待値で比較したい場合"
    en: "Comparing uncertain options by expected value"
  - ja: "シナリオ前提と推奨判断を同時に説明したい場合"
    en: "Explaining the scenario assumptions and the recommendation together"
avoidWhen:
  - ja: "原因を親子へ分解したい場合"
    en: "Decomposing causes into parent and child"
  - ja: "日付依存の並行計画を示したい場合"
    en: "Showing a date-driven parallel plan"
requiredInputs:
  - ja: "2〜4選択肢"
    en: "Two to four options"
  - ja: "各選択肢の確率分岐"
    en: "The probability branches under each"
  - ja: "各結果の価値"
    en: "The value of each outcome"
relatedLayouts: [logic-tree, comparison-table, matrix-2x2]
dataSchema:
  options: "{ id, label, branches[] }[] — 2〜4選択肢"
  branches: "{ id, label, probability, outcomeValue, note? }[] — 各2〜5結果、確率合計100"
sources: []