Simon Willison’s Weblog

4th March 2025 - Link Blog

A Practical Guide to Implementing DeepSearch / DeepResearch. I really like the definitions Han Xiao from Jina AI proposes for the terms DeepSearch and DeepResearch in this piece:

DeepSearch runs through an iterative loop of searching, reading, and reasoning until it finds the optimal answer. [...]

DeepResearch builds upon DeepSearch by adding a structured framework for generating long research reports.

I've recently found myself cooling a little on the classic RAG pattern of finding relevant documents and dumping them into the context for a single call to an LLM.

I think this definition of DeepSearch helps explain why. RAG is about answering questions that fall outside of the knowledge baked into a model. The DeepSearch pattern offers a tools-based alternative to classic RAG: we give the model extra tools for running multiple searches (which could be vector-based, or FTS, or even systems like ripgrep) and run it for several steps in a loop to try to find an answer.

I think DeepSearch is a lot more interesting than DeepResearch, which feels to me more like a presentation layer thing. Pulling together the results from multiple searches into a "report" looks more impressive, but I still worry that the report format provides a misleading impression of the quality of the "research" that took place.