Collaboration is a cornerstone of 21st-century learning, yet teachers continue to face challenges in supporting productive peer interaction. Emerging generative AI tools offer new possibilities for scaffolding collaboration, but their role in mediating in-person group work remains underexplored, especially from the perspective of educators. This paper presents findings from an exploratory qualitative study with 33 K12 teachers who interacted with Phoenix, a voice-based conversational agent designed to function as a near-peer in face-to-face group collaboration. Drawing on playtesting sessions, surveys, and focus groups, we examine how teachers perceived the agent's behavior, its influence on group dynamics, and its classroom potential. While many appreciated Phoenix's capacity to stimulate engagement, they also expressed concerns around autonomy, trust, anthropomorphism, and pedagogical alignment. We contribute empirical insights into teachers' mental models of AI, reveal core design tensions, and outline considerations for group-facing AI agents that support meaningful, collaborative learning.

翻译：协作是21世纪学习的基石，然而教师在支持富有成效的同伴互动方面持续面临挑战。新兴的生成式AI工具为搭建协作支架提供了新的可能性，但它们在调节面对面小组工作中的角色仍未得到充分探索，尤其从教育工作者的视角来看。本文呈现了一项探索性定性研究的结果，该研究涉及33名K12教师，他们与Phoenix进行了互动——这是一个基于语音的会话代理，旨在面对面小组协作中扮演近似同伴的角色。通过游戏测试环节、问卷调查和焦点小组讨论，我们考察了教师如何感知该代理的行为、其对小组动态的影响及其课堂应用潜力。尽管许多教师赞赏Phoenix激发参与度的能力，但他们也对其在自主性、信任、拟人化以及教学一致性方面表达了担忧。我们为教师的AI心智模型提供了实证见解，揭示了核心的设计矛盾，并为支持有意义协作学习的面向小组的AI代理提出了设计考量。