{
  "performance_history": [
    {
      "timestamp": "2025-07-13T12:04:57.580665",
      "correct": false,
      "difficulty": "Easy",
      "item_id": null,
      "topic": "Niko Bellic"
    }
  ],
  "difficulty_scores": {
    "Easy": 0.6400000000000001,
    "Medium": 0.5,
    "Hard": 0.2
  },
  "item_performance": {},
  "last_updated": "2025-07-13T12:04:57.581658"
}