{
  "dataset": "WikiText-2",
  "seed": 42,
  "selection_ratio": 0.2,
  "selected_blocks": 430,
  "variants": {
    "Random": {
      "mean_selection_nll": 6.2888687821321705,
      "test_loss": 5.79670874774456,
      "perplexity": 329.2142477359009
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    "Easy-NLL": {
      "mean_selection_nll": 6.139293526494225,
      "test_loss": 5.783596396446228,
      "perplexity": 324.92565309294514
    },
    "PPL-Factory": {
      "mean_selection_nll": 6.285616204904955,
      "test_loss": 5.814420700073242,
      "perplexity": 335.0972204676031
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  },
  "perplexity_reduction_vs_random_percent": -1.7869739150601902,
  "schema_version": 2,
  "manifest_ref": "reproduction:ppl-factory",
  "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/2607.18199-ppl-factory/metrics/wikitext-2-seed42.json",
    "historical_migration": "historical-metrics-v2-2026-08-09",
    "original_code_commit": "not recorded",
    "dataset_fingerprint": "not recorded in historical artifact"
  }
}