{
  "paper": {
    "arxiv_id": "2607.23749",
    "title": "Breaking the Loop: An Empirical Comparison of Strategies for Novelty and Freshness in YouTube Music",
    "url": "https://arxiv.org/abs/2607.23749",
    "organization": "YouTube Music / Google"
  },
  "dataset": {
    "name": "MovieLens 100K",
    "users": 480,
    "items": 700
  },
  "setup": {
    "adapter": "youtube-freshness",
    "same_split_and_candidates": true
  },
  "baseline": {
    "name": "continuously-trained popularity-biased ranker",
    "hit_at_10": 0.05625,
    "ndcg_at_10": 0.02675943261645708,
    "fresh_hit_at_10": 0.019417475728155338,
    "head_share_at_10": 0.4997916666666667
  },
  "method": {
    "name": "recency + IPS + bias tower removal + SNGP exploration",
    "hit_at_10": 0.05625,
    "ndcg_at_10": 0.025060175546051604,
    "fresh_hit_at_10": 0.019417475728155338,
    "head_share_at_10": 0.35625
  },
  "relative": {
    "hit_at_10_percent": 0.0,
    "ndcg_at_10_percent": -6.350123691936693,
    "fresh_hit_at_10_percent": 0.0,
    "head_share_at_10_percent": -28.720300125052105
  },
  "stages": {
    "serving_recency_boost": true,
    "inverse_propensity_training": true,
    "architecture_bias_tower_removed_at_serving": true,
    "sngp_uncertainty_head": true,
    "same_candidate_generation": true,
    "selected_validation_blend": 0.1,
    "validation_only_model_selection": {
      "hit_at_10": 0.09375,
      "ndcg_at_10": 0.04948933094523425,
      "fresh_hit_at_10": 0.041666666666666664,
      "head_share_at_10": 0.36875
    }
  },
  "paper_results": {
    "uncertainty_weighted_new_release_engagement_percent": 4.33,
    "experiment_arms": 7,
    "daily_users": "millions per arm",
    "primary_window_days": 14
  },
  "scope": "在同一 MovieLens split 上分别执行 serving 调权、IPS、可移除 popularity bias tower 和不确定性探索，并报告新颖度/头部占比；没有 YouTube 连续训练日志。",
  "schema_version": 2,
  "manifest_ref": "reproduction:youtube-freshness",
  "evaluation_protocol": {
    "tier": "l2_public_dataset",
    "seeds": [
      42
    ],
    "formal_comparison": false,
    "claim_policy": "single/few-seed smoke result; do not claim a stable improvement"
  },
  "provenance": {
    "artifact_path": "docs/reproductions/2607.23749-youtube-freshness/metrics/result-seed42.json",
    "historical_migration": "historical-metrics-v2-2026-08-09",
    "original_code_commit": "not recorded",
    "dataset_fingerprint": "not recorded in historical artifact"
  }
}