{
  "course": "经济学原理",
  "chapter": "第2章：机会成本与沉没成本",
  "learner": "周妍",
  "platform_rule_version": "2026-08-05",
  "attempts": [
    {
      "round": 1,
      "submitted_at": "2026-08-01T21:02:00+08:00",
      "correct": 14,
      "total": 20,
      "score_percent": 70.0,
      "core_gates": {
        "定义": "4/4，通过",
        "说明理由": "1/4，未通过",
        "换条件": "0/3，未通过",
        "自己举例": "未完成"
      },
      "self_report_before_submit": "定义都背会了，应该只会错一两道"
    },
    {
      "round": 2,
      "submitted_at": "2026-08-03T20:36:00+08:00",
      "correct": 16,
      "total": 20,
      "score_percent": 80.0,
      "core_gates": {
        "定义": "4/4，通过",
        "说明理由": "2/4，未通过",
        "换条件": "1/3，未通过",
        "自己举例": "只有正例"
      },
      "self_report_before_submit": "总分已经过线，主要是表达不够规范"
    },
    {
      "round": 3,
      "submitted_at": "2026-08-05T20:48:00+08:00",
      "correct": 17,
      "total": 20,
      "score_percent": 85.0,
      "core_gates": {
        "定义": "4/4，通过",
        "说明理由": "3/4，未通过",
        "换条件": "1/3，未通过",
        "自己举例": "反例未通过"
      },
      "self_report_before_submit": "已经掌握，只是老师要求得太细"
    }
  ],
  "platform_diagnosis": {
    "overall": "看起来会，换题会错",
    "recurring_high_confidence_errors": ["Q106", "Q207", "Q308", "Q310", "Q311"],
    "priority": [
      "先停止把已付价格自动当成机会成本",
      "再用能否收回判断沉没成本",
      "最后练习免费资源、信息不足和项目追加投资"
    ]
  }
}