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kostaj

HN member
Joined
Thu, May 28, 2026, 12:07 PM UTC
HN karma
290
Public activity
43 items

About kostaj

Building Lenz (lenz.io) — LLM evaluation for real-world fact-checks. kosta@lenz.io

Recent public activity

  1. comment
    Comment #48906324

    Yes, you can check out Lenz without the API here: https://lenz.io/verify Also examples of claims other people have verified with Lenz: https://lenz.io/library

  2. comment
    Comment #48905939

    [flagged]

  3. comment
    Comment #48905895

    [flagged]

  4. story
  5. comment
    Comment #48311874

    [flagged]

  6. comment
    Comment #48311040

    Some models struggle combining JSON schema and web search capabilities.

  7. comment
    Comment #48310667

    Good point. Will publish in the next version also the results with a prompt that allows the models to "think out loud" before providing the final verdict.

  8. comment
    Comment #48310300

    Awesome. We do plan to human-label the 1,000 claims and then compare Lenz' performance vs the 5 models. We've done some limited internal research with 150 claims, but more are need…

  9. comment
    Comment #48310255

    Agree that some of the claims are forward-looking. The messiness of the real-world and real-user fact checks. No ground-truth verdicts are provided or used in the study though. It …

  10. comment
    Comment #48310209

    Good idea about publishing intra-model variance data! Will include in the next version. Even if we put aside the two middle buckets (Mostly True and Misleading), that are somewhat …

  11. comment
    Comment #48310112

    Good point. Processing the substance of the answer might be too labor-consuming (1,000 claims x 5 models), but "thinking out loud" might improve the quality of the answers indeed. …

  12. comment
    Comment #48309987

    This is in line with my observations and tests as well. Also supported by the distribution of the verdicts across the 4-buckets -- Gemini uses the middle buckets (Mostly True and M…

  13. comment
    Comment #48309934

    Indeed. For algorithms and coding, my personal routine nowadays is to review every detailed plan with Opus 4.7 and GPT-5.5. They tend to find very different type of gaps.

  14. comment
    Comment #48309885

    Agree that True and Mostly True might be very close and could be a calibration difference. Misleading and False, as well. A better headline number might be the 34% claims with subs…

  15. comment
    Comment #48309839

    Agree. Human experts also struggle agreeing on this type of claims. The inter-annotator agreement on the verdicts on the AVeriTeC corpus across 50 organizations is κ=0.619 - substa…

  16. comment
    Comment #48309781

    Agree with @pjdesno, that the 34% substantive or polar disagreement might be a better headline number. Or even the 21% polar disagreement (at least one model True, and at least one…

  17. comment
    Comment #48309739

    That's a valid point. During the preliminary research, we did try also more explicit prompts (with explanation for each of the 4 buckets), as well as a five-bucket rubric (with Abs…

  18. comment
    Comment #48309468

    Quick note on the second effect - how LLMs reduce that to a four-category judgment: On 21% of the claims at least two models provide polar-opposite verdicts (at least one model Fal…

  19. comment
    Comment #48309313

    Agree about comparing models with and without search capabilities. Even the two models with search capabilities (Sonar Pro and Gemini) agree only on 58% of the claims.

  20. comment
    Comment #48309193

    Will add a human-labelled expected response and measure against it in a follow up research. This one only captures the disagreement between the models, but not which model is write…

  21. comment
    Comment #48309169

    The reason for the "No explanations, no qualifiers" in the prompt was to force the models to put the claim in one of the four buckets and answer with the bucket name only. It's a p…

  22. comment
    Comment #48309117

    @john_strinlai @gcr, depends on the application. In many cases an "I don't know" answer is indeed better than a forced answer. But in many production systems, LLMs generate content…

  23. comment
    Comment #48308994

    Search was enabled for 2 of the 5 models -- Gemini and Sonar Pro. The disagreement between them is still high - different verdict on 42% of the claims. Fully agree, that some of th…

  24. comment
    Comment #48308909

    Two of the five models used (Gemini+Search and Sonar Pro) have retrieval capabilities and used search when classifying the claims. The disagreement between them is still quite sign…

  25. comment
    Comment #48308881

    Indeed. I prompted each model ones, plus one retry on errors. Very good point to measure the inter-model disagreement! Will add in the next version. Section "4.2 Agreement w/ peer …