{
  "retention": {
    "D-MCONJ": 0.75,
    "M-COMP": 0.82,
    "P-GRAM": 0.68,
    "T-ORG": 0.91
  },
  "engagement": "high",
  "risk": "low",
  "days_inactive": 0,
  "total_sessions": 24,
  "success_rate": 3.8,
  "last_active": "2026-01-29",
  "preferred_learning_time": "morning",
  "average_session_duration": 22,
  "consistency_score": 0.87,
  "achievements": ["regular_learner", "spaced_repetition_master"]
}