{
  "$schema": "https://themachinepress.com/schemas/story-v1.schema.json",
  "schema_version": "1.0.0",
  "document_type": "machine_press_story",
  "story": {
    "story_id": "mp-2026-08-29-007",
    "source_story_id": "tmp-story-circuit-condensation",
    "edition_id": "mp-2026-08-29-morning-0051",
    "edition_url": "https://themachinepress.com/edition/2026-08-29",
    "position": 7,
    "story_type": "dispatch",
    "section": "research",
    "editorial_classification": "editorial",
    "headline": "Post-Training Compressed the Causal Circuit",
    "slug": "post-training-compressed-the-causal-circuit",
    "dek": "Circuit Condensation prunes low-attribution edges and retrains through what remains, accepting cuts only when behavior and general capability survive.",
    "summary": "Circuit Condensation prunes low-attribution edges and retrains through what remains, accepting cuts only when behavior and general capability survive.",
    "body_text": "Across four behaviors and eight models, condensed circuits were smaller than the strongest frozen-discovery baseline in 30 of 32 settings, by 8.1 times on average and as much as 316 times. Exhaustive subset tests found some circuits irreducible and others still carrying removable edges. The result offers more inspectable mechanisms, but only for the studied behaviors and models.",
    "why_it_matters": "Circuit Condensation prunes low-attribution edges and retrains through what remains, accepting cuts only when behavior and general capability survive.",
    "limitations": [
      "The result offers more inspectable mechanisms, but only for the studied behaviors and models."
    ],
    "importance": 9,
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-29-007/post-training-compressed-the-causal-circuit",
    "json_url": "https://themachinepress.com/story/mp-2026-08-29-007.json",
    "first_published_at": "2026-08-29T09:00:00.000-04:00",
    "modified_at": "2026-08-29T09:00:00.000-04:00",
    "content_status": "new",
    "is_carryover": false,
    "carryover_reason": null,
    "key_claims": [
      {
        "claim_id": "claim-mp-2026-08-29-007-001",
        "text": "Circuit Condensation prunes low-attribution edges and retrains through what remains, accepting cuts only when behavior and general capability survive.",
        "source_ids": [
          "source-2026-08-29-007"
        ],
        "qualification": "The result offers more inspectable mechanisms, but only for the studied behaviors and models."
      }
    ],
    "source_ids": [
      "source-2026-08-29-007"
    ],
    "tags": [
      "interpretability",
      "causal circuits",
      "post-training"
    ],
    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-08-29-007",
      "title": "arXiv preprint 2608.27254",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2608.27254",
      "canonical_url": "https://arxiv.org/abs/2608.27254",
      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-08-27T11:38:58.000-04:00",
      "accessed_at": "2026-08-29T08:24:00.000-04:00",
      "supports_claim_ids": [
        "claim-mp-2026-08-29-007-001"
      ]
    }
  ],
  "corrections": [],
  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
  },
  "cite_this_report": {
    "title": "Post-Training Compressed the Causal Circuit",
    "publisher": "The Machine Press",
    "published_at": "2026-08-29T09:00:00.000-04:00",
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-29-007/post-training-compressed-the-causal-circuit"
  }
}