On LLM Wizards: Identifying Large Language Models' Behaviors for Wizard of Oz Experiments
Jingchao Fang, Nikos Arechiga, Keiichi Namaoshi, Nayeli Bravo, Candice Hogan, David A. Shamma
TL;DR
This paper tackles the challenge of safely using large language models (LLMs) as Wizards in Wizard of Oz experiments. It proposes a two-stage lifecycle: Stage 1 uses LLM-to-LLM interactions (WoLs with Simulacrums) to rapidly probe for harmful or repetitive behaviors, aided by a heuristic evaluation framework that measures toxicity, sentiment, semantic/sequence similarity, readability, and topic alignment; Stage 2 reintroduces human Participants to validate and refine the WoLs in realistic settings. Through Study 1 (LLMs-to-LLMs) and Study 2 (LLMs-to-Participants), the authors identify both strengths (non-toxicity, generally positive sentiment, topic coherence) and failure modes (increasing repetition, occasional lack of empathy, pushiness), and provide concrete guardrails (prompt design, finetuning, retrieval-augmentation, and a policy-like constitution) to guide safe deployment. The work offers a practical blueprint for scalable, responsible WoZ experiments with LLMs, enabling rapid iteration while safeguarding participants and data integrity. These insights have broad implications for developing scalable, human-centered AI in conversational design and design-space exploration.
Abstract
The Wizard of Oz (WoZ) method is a widely adopted research approach where a human Wizard ``role-plays'' a not readily available technology and interacts with participants to elicit user behaviors and probe the design space. With the growing ability for modern large language models (LLMs) to role-play, one can apply LLMs as Wizards in WoZ experiments with better scalability and lower cost than the traditional approach. However, methodological guidance on responsibly applying LLMs in WoZ experiments and a systematic evaluation of LLMs' role-playing ability are lacking. Through two LLM-powered WoZ studies, we take the first step towards identifying an experiment lifecycle for researchers to safely integrate LLMs into WoZ experiments and interpret data generated from settings that involve Wizards role-played by LLMs. We also contribute a heuristic-based evaluation framework that allows the estimation of LLMs' role-playing ability in WoZ experiments and reveals LLMs' behavior patterns at scale.
