RAG Optimization: Keep Key Information at the Edges of Context

Stanford's "lost in the middle" research (now mainstream practice) confirms that LLM attention degrades for information placed in the middle of long contexts. For RAG pipelines: place the most critical retrieved chunks at the very beginning or end of the prompt. Also: resist the urge to dump everything into context — a 2025 Chroma study found every model tested performed worse as input volume grew. Optimal standalone prompt length is 150–300 words; beyond that, compress with summarization before retrieval.

---

Sources: Stack AI Blog · Regal.ai