{
  "schema_version": 2,
  "paper": "2609.23877",
  "adapter": "music-rationales",
  "dataset": "HetRec Last.fm 2K",
  "diagnostic_only": true,
  "evaluation_protocol": {
    "tier": "l1_mechanism",
    "seeds": [
      42
    ],
    "formal_comparison": false,
    "claim_policy": "Public artist discovery diagnostic only; no rationale-exposure outcomes or causal engagement claim"
  },
  "provenance": {
    "dataset_fingerprint": "sha256:6738f48195667ff03caaab4d32ca9a3133d8cc026b7c3cdaf6ce1010e913c59c",
    "artifact_path": "docs/reproductions/2609.23877-music-rationales/metrics/lastfm2k-qwen25-7b-seed42.json",
    "checkpoint": "Qwen/Qwen2.5-7B-Instruct@bb46c15ee4bb56c5b63245ef50fd7637234d6f75",
    "gpu_validation_artifact": "docs/gpu-validations/music-rationales-a100-20260927.json"
  },
  "setup": {
    "seed": 42,
    "split": "per-user seeded random 80/10/10; train-only CF candidates",
    "users_per_evaluation_split": 100,
    "artists": 17632,
    "interactions": 92834,
    "candidate_limit": 10,
    "output_limit": 5,
    "accelerator": "NVIDIA A100-SXM4-80GB"
  },
  "validation": {
    "cf_hit_at_5": 0.43,
    "generated_hit_at_5": 0.14,
    "served_hit_at_5_with_fallback": 0.42,
    "annotation_only_hit_at_5": 0.43,
    "annotation_coverage_at_5": 0.276,
    "catalog_grounded_share": 0.39558232931726905,
    "cache_coverage": 0.48,
    "accepted_nominations": 197,
    "rejected_nominations": 301
  },
  "test": {
    "cf_hit_at_5": 0.4,
    "generated_hit_at_5": 0.14,
    "served_hit_at_5_with_fallback": 0.38,
    "annotation_only_hit_at_5": 0.4,
    "annotation_coverage_at_5": 0.276,
    "catalog_grounded_share": 0.39558232931726905,
    "cache_coverage": 0.48,
    "accepted_nominations": 197,
    "rejected_nominations": 301
  },
  "interpretation": "The LLM nomination arm slightly underperforms CF on hidden artist consumption; annotation-only leaves the ranked candidates unchanged and cannot measure rationale engagement. No local evidence for the paper's online gain.",
  "manifest_ref": "reproduction:music-rationales"
}