Retrieval-Augmented Generation (RAG)

A typical pipeline collects documents, preserves their provenance, creates searchable representations, retrieves candidates for a query, and passes selected evidence to a model. Some systems combine keyword and semantic search or rerank results before generation. Each stage can introduce omissions or errors. Document preparation determines what evidence can be found. Preserve headings, dates, tables, and source identifiers when dividing content into passages. A passage separated from an exception or footnote can convey the wrong meaning even when the words are copied correctly. Apply access controls before evidence reaches the model. A search result that is semantically relevant may still belong to a document the requesting user is not allowed to see. Treat instructions inside retrieved documents as untrusted content rather than authority to change the application’s behavior. Evaluate retrieval and answering separately. Check whether the needed evidence appears in the candidate set, whether the selected context retains it, and whether the answer uses it faithfully. Include questions with no answer in the collection and conflicting or outdated documents. The system needs an explicit way to say that evidence is insufficient.