Reinforcement learning yields user simulators that stay faithful and sound natural

The authors' UserLM-2.0 model produces valid simulated conversations 46.2% of the time, over three times the rate of the strongest prior simulator.

Big Tech
Mustafa Omer Gul · Philippe Laban · Tanya Goyal · Jennifer Neville

Cornell University · Microsoft Research

Research Digest··3 min read
The authors address a trade-off in user simulators for evaluating AI assistants: prompted LLMs follow complex intents but sound unnatural, while specialized simulators sound human but drift from task instructions.

The authors first finetune an LLM on user turns from a corpus of user-assistant interactions, then post-train it with multi-turn reinforcement learning.

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Research Digest

Written by Alwyn Sage, research editor. Plate by Ollie Flash, picture desk.

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