This article examines why basic text extraction from PDFs often falls short when building Retrieval Augmented Generation (RAG) pipelines. It highlights how losing visual layout information results in lost semantic context, affecting model accuracy and retrieval performance. The author introduces the concept of two critical layers within a document: the physical layer involving raw character data and coordinates, and the logical layer that constructs meaning through structural elements like headings, tables, and multi-column layouts.
- Why standard text extraction limits RAG performance
- Understanding physical versus logical PDF layers
- The role of layout awareness in preserving semantic context