Datalab finds judging errors on 68 of 200 pages in olmOCR-bench, shares 5 checks

VikParuchuri · x · 2026-11-05

Datalab's Vik Paruchuri argues you should always be skeptical of benchmarks, using olmOCR-bench as a case study: olmOCR-2 scores 100% on 119 of 200 pages, yet judges found errors on 68 of those pages, and the benchmark's header rule favors models that omit headers. The accompanying post lays out 5 checks before trusting a parsing benchmark number: score the ground truth as a parser, corrupt 5% of digits and see if the score drops, test format invariance on tables, leave out a page and see if it notices, and read 20 failures to verify they're real errors.

Related event: Datalab Finds Half of Document Parsing Benchmarks Unreliable(2 posts)→

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