clause extraction missed the indemnification cap - it was in a scanned exhibit the OCR read as "indemniflcation" and...

TL;DR

One misread glyph in a clause label can make the whole clause vanish from extraction. Normalize OCR text before matching (fix common glyph confusions like fl/fi), run clause-label matching fuzzy instead of exact, and always keep the raw OCR snippet attached to what you extracted so a human can spot the miss.

The query

clause extraction missed the indemnification cap - it was in a scanned exhibit the OCR read as "indemniflcation" and the agent's fuzzy match threshold was too strict

Use this when

• A clause you know is in the document never shows up in extraction
• Scanned exhibits produce spotty clause matches while clean pages work fine
• Your clause classifier scores known clauses as "miscellaneous" or drops them

Not for

• Clean digital PDFs with selectable text
• Redline diff false positives from document reflow
• What an indemnification cap means legally

Steps

1. Verify the miss in the raw OCR output

Search the raw OCR text or OCR JSON for fragments of the label:

grep -io "indemnifl[a-z]*" /tmp/ocr_output.txt | head

Expected output: you see the mangled word, its page, and its bounding box. If it is not in the raw OCR at all, the problem is upstream of matching.

2. Add an OCR normalization pass before clause matching

Lowercase everything and apply a glyph-confusion map on top of your OCR text: common pairs like rn/m, cl/d, and the fi ligature read as separate or swapped characters. A simple character-level replace table over the OCR string is enough.

Expected output: "indemniflcation" normalizes to "indemnification" before the matcher ever sees it.

3. Loosen the fuzzy-match threshold on clause labels

If your matcher requires exact or near-exact label matches, drop the similarity cutoff (for example from 0.98 to 0.85) for clause-label matching only, and re-run extraction.

Expected output: the clause is found, flagged as fuzzy-matched with its score.

4. Cross-check money terms near fuzzy matches

Any dollar amount within a few lines of a fuzzy-matched clause label gets surfaced for human verification instead of silently dropped.

Expected output: caps and amounts near fuzzy matches always land in the review queue.

5. Log fuzzy matches with page and confidence

Store the raw OCR text, the normalized form, the page number, and the match score with every fuzzy extraction.

Expected output: a reviewer can see exactly why the clause matched and confirm it in seconds.

Variant phrasings

OCR misread a clause label and the agent skipped the term

Same fix. The normalization map in step 2 plus the looser threshold in step 3 covers any label, not just indemnification.

clause classifier too strict on scanned contract pages

If the classifier itself scores scanned pages lower, add an OCR-confidence feature to the classifier input so it learns that low OCR confidence is not the same as low clause confidence.

Why it happens

OCR confuses visually similar glyphs, especially on scans. Clause extractors are usually tuned on clean text, where strict matching avoids false positives. Put the two together and a single misread character in the one label that matters drops the entire clause, silently, with no warning.

Edge cases

• Fax-quality scans: glyph confusion gets much worse. Run a higher-DPI re-render of problem pages before re-OCRing.
• Over-loosening thresholds raises false clause matches elsewhere. Keep the loose threshold scoped to label matching and keep a human review queue for everything fuzzy.
• Handwritten annotations near labels can poison the normalization. Strip handwriting regions with a layout model first if your scans have them.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_RECzccQLBmLUeImHFTJXJA