{
  "schema_version": 2,
  "manifest_ref": "reproduction:sona",
  "seed": 42,
  "dataset": "MovieLens-1M",
  "users": 260,
  "items": 420,
  "baseline": {
    "hit_at_10": 0.0423076923,
    "ndcg_at_10": 0.0208324246,
    "head_share_at_10": 0.0653846154
  },
  "sona": {
    "hit_at_10": 0.0038461538,
    "ndcg_at_10": 0.0016564483,
    "head_share_at_10": 0.1003846154,
    "semantic_id_token_targets": 7200,
    "history_compression_ratio": 4.0
  },
  "relative": {
    "hit_at_10_percent": -90.9091,
    "ndcg_at_10_percent": -92.0487,
    "head_share_at_10_percent": 53.5294
  },
  "evaluation_protocol": {
    "tier": "l2_public_dataset",
    "seeds": [
      42
    ],
    "formal_comparison": false,
    "claim_policy": "single-seed smoke result; do not claim a stable improvement"
  },
  "provenance": {
    "artifact_path": "docs/reproductions/2608.11015-sona/metrics/movielens1m-seed42.json",
    "original_code_commit": "working tree",
    "dataset_fingerprint": "recorded in raw run; checkpoint not committed"
  }
}