{
  "slug": "japan-study-time-achievement-2026",
  "source_scope": {
    "assessment": "令和8年度全国学力・学習状況調査",
    "grades": [
      "小学校第6学年",
      "中学校第3学年"
    ],
    "question_numbers": [
      23,
      25,
      "32-1",
      "32-2"
    ],
    "unit": "国語・算数/数学は平均正答率、英語3技能はIRTスコア"
  },
  "contrasts": {
    "weekday": {
      "primary": {
        "japanese_high_minus_low": 22.5,
        "math_high_minus_low": 27.4
      },
      "middle": {
        "japanese_high_minus_low": 14.0,
        "math_high_minus_low": 22.3,
        "english_irt_high_minus_low": 108
      }
    },
    "weekend": {
      "primary": {
        "japanese_high_minus_low": 22.2,
        "math_high_minus_low": 29.6
      },
      "middle": {
        "japanese_high_minus_low": 16.8,
        "math_high_minus_low": 26.2,
        "english_irt_high_minus_low": 126
      }
    },
    "reflection": {
      "primary": {
        "japanese_high_minus_low": 22.1,
        "math_high_minus_low": 24.5
      },
      "middle": {
        "japanese_high_minus_low": 17.2,
        "math_high_minus_low": 24.9,
        "english_irt_high_minus_low": 100
      }
    }
  },
  "rank_associations": {
    "weekday": {
      "primary": {
        "japanese_spearman": 1.0,
        "math_spearman": 1.0
      },
      "middle": {
        "japanese_spearman": 0.943,
        "math_spearman": 1.0,
        "english_irt_spearman": 1.0
      }
    },
    "weekend": {
      "primary": {
        "japanese_spearman": 1.0,
        "math_spearman": 1.0
      },
      "middle": {
        "japanese_spearman": 1.0,
        "math_spearman": 1.0,
        "english_irt_spearman": 1.0
      }
    },
    "reflection": {
      "primary": {
        "japanese_spearman": 1.0,
        "math_spearman": 1.0
      },
      "middle": {
        "japanese_spearman": 1.0,
        "math_spearman": 1.0,
        "english_irt_spearman": 1.0
      }
    }
  },
  "response_shares": {
    "weekday_at_least_one_hour_pct": {
      "primary": 50.4,
      "middle": 61.8
    },
    "reflection_affirmative_pct": {
      "primary": 79.3,
      "middle": 64.6
    }
  },
  "interpretation_boundary": "公表された群平均の記述比較。個票・共変量調整・因果推定・最適時間の推定ではない。",
  "plateau_checks": {
    "middle_weekday_japanese_3h_plus_minus_2to3h": -0.4,
    "middle_weekday_math_3h_plus_minus_2to3h": 0.9,
    "primary_weekday_math_3h_plus_minus_2to3h": 11.4
  }
}