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Confidence Has a Timing Problem: What SFT, RL, and Distillation Change in Reasoning Models

TL;DR for operators A reasoning model can have useful confidence at one point in its workflow and misleading confidence at another. In a controlled comparison using the same Qwen2.5-7B-Instruct backbone and reasoning-data mixture, on-policy distillation produced the strongest average signal for estimating difficulty before reasoning, supervised fine-tuning supplied particularly useful confidence for stopping weak traces during generation, and reinforcement learning gained the most from confidence-based filtering after traces were complete.1 ...

August 14, 2026 · 9 min · Zelina
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Running Is Not Correct: Why Scientific Code Needs Graded Verification

TL;DR for operators For generated engineering code, successful execution should be treated as a feasibility check, not a correctness certificate. In the paper’s 7B ablation, reinforcement learning based only on program validity reaches pass@1 of 0.58 and pass@8 of 0.76. Adding continuous trajectory accuracy raises those figures to 0.71 and 0.84. The mechanism is straightforward. Generated solver code must first run, return the required output shape, and avoid non-finite values. Programs that clear those checks are then graded by how closely their numerical trajectories match hidden references and, where available, how consistent their outputs are with the governing PDE. ...

August 14, 2026 · 8 min · Zelina
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Control in Degrees: Why Reliable AI Needs Calibrated Intervention

TL;DR for operators Reliability is often treated as a binary control problem: approve or reject an agent action, preserve or replace a learned component. The evidence here points to a second question that can matter just as much: how strongly should the system intervene, where, and under what conditions? The clearest technical example comes from continual reinforcement learning. In a 400-million-step SlipperyAnt stress test, CPR recorded zero policy collapses across all 15 seeds under the paper’s main collapse criterion, while Adam and binary-reset baselines experienced collapses. Rather than fully replacing every selected component, CPR changes it by an amount tied to measured utility—preserving more useful learned state while refreshing low-utility state more aggressively. ...

August 11, 2026 · 8 min · Zelina
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One Demonstration Is Not One Deployment: Regrind’s Real Robotics Lesson

TL;DR for operators A robotics team can teach a many-fingered hand to use scissors or a screwdriver without first collecting a large robot-specific teleoperation dataset. The critical step is not simply copying human joint positions, but preserving how the hand surrounds, supports, and moves the object. Regrind converts one three-dimensional human hand-object demonstration into a feasible robot reference, then uses that reference to guide reinforcement learning near promising parts of the task rather than forcing it to discover the behavior from random states. ...

August 10, 2026 · 8 min · Zelina
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Reasoning Is a Configuration, Not a Switch

TL;DR for operators A legal-translation team may assume it can train a model normally and later enable extra intermediate text whenever higher quality is needed. In this experiment, that deployment-only change produced nearly the same translation quality at far greater output volume. For Qwen3.5 9B, using reasoning during both training and inference reached COMET 82.50 with 6.27 million output tokens. Enabling reasoning only at inference reached COMET 82.32 with 20.67 million tokens—more than three times the output for slightly lower quality. ...

August 6, 2026 · 9 min · Zelina
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Fair on Clean Data, Fragile After Fake Profiles

TL;DR for operators A platform can evaluate a recommender on clean historical data, observe only a small performance gap between groups, and reasonably approve it for retraining. That approval does not show how the same training process will respond when coordinated fake accounts deliberately shape the next batch of user interactions. In the reported experiments, fake profiles widened subgroup disparities even when the target recommender used fairness-aware training. Across the tested models, the paper’s SRLFA method generally produced larger disparities than the adapted attack baselines, with the largest reported effects appearing on the fairness-aware Last.fm LightGCN target. ...

August 1, 2026 · 8 min · Zelina
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Fewer Extreme Costs, Higher Average Cost: Risk-Aware Planning Beyond Expected Reward

TL;DR for operators Two autonomous policies can produce similarly acceptable average results while one occasionally causes a severe operational failure. Risk-aware planning matters because averages alone cannot reveal that difference. fileciteturn0file0 The paper evaluates the full pattern of states and actions accumulated during each run, then gives progressively more weight to costly outcomes in the resulting distribution. This allows the planner to reduce exposure to severe trajectories rather than merely adding a fixed penalty to expected reward. ...

July 31, 2026 · 9 min · Zelina
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A Full Distribution Is Not a Risk Certificate

TL;DR for operators A team is deciding whether an AI risk dashboard should trigger a safer action, an operational alert, or a governance review. The system predicts a range of possible returns for each action rather than only an average, so its output may appear to provide stronger evidence about worst-case outcomes. ...

July 30, 2026 · 8 min · Zelina
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The Missing Present Is a Distribution: DUPO for Delayed Control

TL;DR for operators A control system must act now even when its latest sensor reading describes an earlier moment. The usual response is to predict the missing present and let the policy act on that reconstruction. In a stochastic system, however, the same delayed message can correspond to several plausible current states—not one hidden answer waiting to be recovered. ...

July 27, 2026 · 8 min · Zelina
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Look Again Before You Answer: Visual RAG Needs a Search Policy

TL;DR for operators A visual support assistant shown an unfamiliar machine, product, bird, or venue cannot answer by retrieval alone. It must first determine what the image depicts, then locate the missing fact, while deciding whether another search is worth the delay. A wrong first match can redirect every later step toward the wrong entity. ...

July 23, 2026 · 8 min · Zelina