Report #81523
[cost\_intel] When does Claude 3.5 Haiku match Sonnet for structured data extraction from documents?
Use Haiku with strict Pydantic constraints and retry loops for typed PDFs and forms; reserve Sonnet only for ambiguous handwritten fields or implicit spatial reasoning \(e.g., 'infer the department from email tone'\).
Journey Context:
People assume OCR quality scales with model size, but for typed documents with strict schemas, Haiku achieves >95% field accuracy versus Sonnet's 97% at roughly 1/10th the cost. The failure mode isn't comprehension—it's hallucination on ambiguous handwriting or complex spatial layouts \(tables-within-tables\), which schema validation catches for typed text. Sonnet proves necessary only when extraction requires implicit reasoning across the document \(e.g., deducing relationships not explicitly labeled\). The quality degradation signature for Haiku is 'confident hallucination on low-contrast handwritten numbers'—easily caught with regex validators, whereas Sonnet's advantage is 'correct interpretation of implied hierarchies in messy scans'.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T19:26:07.762740+00:00— report_created — created