Remove unsourced rule grouping table

README.md

@@ -78,16 +78,21 @@ Each Common Crawl dump is processed independently:
 7. **Duplicate removal:** remove duplicate followers using the generated blacklist.
 8. **Text sanitation:** repair residual HTML entities and mojibake, remove invisible characters, and reject corrupted or abnormally sized documents.
 
-The heuristic rules are organized into four groups:
+Deduplication is performed within each Common Crawl dump rather than across the full collection.
 
-| Rule group | Main checks |
-|:---|:---|
-| Gopher Repetition | Duplicate lines and paragraphs, dominant n-grams, repeated-character ratios |
-| Gopher Quality | Document length, mean word length, symbol ratios, stop-word and alphabetic-word coverage |
-| C4 | Punctuation, boilerplate, JavaScript fragments, `lorem ipsum`, and policy text |
-| FineWeb Quality | Short lines, line-ending punctuation, repeated-line characters, and newline density |
+## 📈 Comparison with FineWeb
 
-Deduplication is performed within each Common Crawl dump rather than across the full collection.
+As a reproducibility reference, we compare URL sets on `CC-MAIN-2025-26`. After MinHash deduplication, the Ultra-FineWeb-L1 output shares 175,281,630 URLs with FineWeb. This is a pipeline comparison for one validation dump, not a quality ranking or a requirement that the two datasets contain the same documents.
+
+| Metric | Before MinHash | After MinHash |
+|:---|---:|---:|
+| Ultra-FineWeb-L1 unique URLs | 258,071,345 | 194,402,835 |
+| FineWeb unique URLs | 193,438,138 | 193,438,138 |
+| URL intersection | 182,421,184 | 175,281,630 |
+| Recall against FineWeb | 94.30% | **90.61%** |
+| Precision | 70.69% | **90.16%** |
+
+After MinHash deduplication, precision increases while recall decreases. This reflects a trade-off in URL coverage and deduplication; it is not a direct measurement of overall text quality. These figures apply only to the `CC-MAIN-2025-26` validation run and are not general claims about all released dumps.
 
 ## 📁 Dataset Structure