Atom by Atom, Better Research: How Fine-Grained Rewards Make Agentic Search Smarter
If you’ve ever watched a web agent swing from elegant reasoning to face‑plants on basic facts, you’ve met the limits of outcome‑only training. Atom‑Searcher proposes a simple but radical fix: stop treating the whole reasoning trace as one monolith. Instead, break it down into Atomic Thoughts—the minimal, functional units of reasoning—and supervise them directly with a Reasoning Reward Model (RRM). Then blend those process‑level rewards with the final answer score using a decaying curriculum. The result? More stable training, deeper search behavior, and better generalization across in‑ and out‑of‑domain QA. ...