estimated MMLU contamination across public web corpora; clean-mirror retests drop scores high-single to low-double digits
~29%observed
| Value kind | observed — Reported measurements, counts, and specifications keep the precision and scope stated by their source; an exact specification is not treated as a range. |
|---|---|
| As of | 2025 |
| Source | Association for Computational Linguistics |
| Review | checking…review by 2026-08-22 · standard cadence |
| Recorded changes | last 2026-07-14 · 2 revisions tracked |
| Claim id | estimated-mmlu-contamination-across-public-web |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.