Retrieval

In the world of Retrieval-Augmented Generation (RAG), most systems still treat document retrieval like a popularity contest — fetch the most relevant-looking text and hope the generator can stitch the answer together. But as any manager who has tried to merge three half-baked reports knows, relevance without completeness is a recipe for failure. A new framework, Compositional Answer Retrieval (CAR), aims to fix that. Instead of asking a retrieval model to find a single “best” set of documents, CAR teaches it to think like a strategist: break the question into its components, retrieve for each, and then assemble the pieces into a coherent whole. ...

Most “smart” RAG stacks are actually compulsive googlers: they fetch first and think later. UR² (“Unified RAG and Reasoning”) flips that reflex. It trains a model to reason by default and retrieve only when necessary, using reinforcement learning (RL) to orchestrate the dance between internal knowledge and external evidence. Why this matters for builders: indiscriminate retrieval is the silent cost center of LLM systems—extra latency, bigger bills, brittle answers. UR² shows a way to make retrieval selective, structured, and rewarded, yielding better accuracy on exams (MMLU‑Pro, MedQA), real‑world QA (HotpotQA, Bamboogle, MuSiQue), and even math. ...

Retrieval-Augmented Generation (RAG) is often hailed as a cure-all for domain adaptation and factual accuracy in large language models (LLMs). By injecting external context at inference time, RAG systems promise to boost performance on knowledge-intensive tasks. But a new paper, RAG in the Wild (Xu et al., 2025), reveals that this promise is brittle when we leave the sanitized lab environment and enter the real world of messy, multi-source knowledge. ...

In the AI race to make large language models both factual and reasoned, two camps have emerged: one focused on retrieval-augmented generation (RAG) to fight hallucination, the other on long-chain reasoning to mimic logic. But neither wins alone. This week’s survey by Li et al. (2025), Towards Agentic RAG with Deep Reasoning, delivers the most comprehensive synthesis yet of the field’s convergence point: synergized RAG–Reasoning. It’s no longer a question of whether retrieval helps generation or reasoning helps retrieval—but how tightly the two can co-evolve, often under the coordination of autonomous agents. ...