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    "story_id": "mp-2026-09-03-001",
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    "section": "robotics",
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    "headline": "The Best Imagined Future Picked the Wrong Controller",
    "slug": "the-best-imagined-future-picked-the-wrong-controller",
    "dek": "Across 24 sensing conditions, a long measurement-free rollout chose a different estimator from the closed-loop optimum 18 times.",
    "summary": "Across 24 sensing conditions, a long measurement-free rollout chose a different estimator from the closed-loop optimum 18 times.",
    "body_text": "A controlled differential-drive study compared six state estimators by replay error, a 20-step measurement-free rollout and actual closed-loop path tracking under biased odometry and intermittent landmarks. Replay position error tracked closed-loop cross-track error more closely than rollout error, with Spearman correlations of 0.923 and 0.774; replay selected a different estimator from the closed-loop optimum in 5 of 24 conditions, while the rollout metric did so in 18. Long predictions remained useful when regular measurement corrections were preserved, making the sensing and update schedule part of the evaluation—not a detail to omit.",
    "why_it_matters": "Across 24 sensing conditions, a long measurement-free rollout chose a different estimator from the closed-loop optimum 18 times.",
    "limitations": [
      "Long predictions remained useful when regular measurement corrections were preserved, making the sensing and update schedule part of the evaluation—not a detail to omit."
    ],
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    "first_published_at": "2026-09-03T09:00:00.000-04:00",
    "modified_at": "2026-09-03T14:20:28.218-04:00",
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        "text": "Across 24 sensing conditions, a long measurement-free rollout chose a different estimator from the closed-loop optimum 18 times.",
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        "qualification": "Long predictions remained useful when regular measurement corrections were preserved, making the sensing and update schedule part of the evaluation—not a detail to omit."
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    "tags": [
      "world models",
      "closed-loop control",
      "robot evaluation"
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    {
      "source_id": "source-2026-09-03-001",
      "title": "arXiv preprint 2609.02811",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.02811",
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      "published_at": "2026-09-02T12:52:30.000-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "The Best Imagined Future Picked the Wrong Controller",
    "publisher": "The Machine Press",
    "published_at": "2026-09-03T09:00:00.000-04:00",
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