PDF table rows become misaligned in RAG: how do you validate parsed evidence?

Map the incorrect answer to a particular table cell

This applies when an amount is assigned to the previous row, year columns become mixed or repeated page headers become ordinary data. Select the page containing the failed cell and necessary adjacent pages. Preserve the original PDF, copyable text and parsed structure. A screenshot aids visual comparison but does not show the fields actually supplied to retrieval.

Check row and column coordinates, headers and page continuation

Check cell row and column indices and merged spans, keeping each value tied to its header. For multi-page tables, inspect repeated headings, continuation labels and unit changes. Compare OCR against the source image, especially decimal points and minus signs. If parsing converts an empty cell into zero, the model cannot reliably reconstruct the original meaning.

Preserve table structure before creating citable chunks

Prefer extraction that preserves table structure and create readable records with headers, row identifiers and page numbers. Make inheritance across complex merged cells explicit or convert them into individual records instead of splitting at arbitrary character counts. Verify a small set of pages before bulk processing so incorrect structures do not enter the knowledge base at scale.

Test same-name rows and deliberately empty cells

Test repeated names in different rows, continued records across pages and deliberately blank cells, verifying that answers point to the correct location. Check amounts and units together, not numeric resemblance alone. Success requires correct extraction and correct citation. Keep unverified values uncertain instead of automatically filling them from adjacent cells.

This article ran no new paid document-parsing task and makes no claim that a layout model handles every PDF without errors. Scan quality, nested tables and reading order affect extraction. High-precision business data still needs human review. Clear rendering does not establish correct machine extraction, and retrieving more chunks cannot repair misaligned records.