xAI's large language model, Grok, is called by millions of people each week on the social media platform X. Prior work characterizing how large language models are used has focused on private, one-on-one interactions. Grok's deployment on X represents a major departure from this setting, with interactions occurring in a public social space. In this paper, we systematically sample three months of interaction data to investigate how, when, and to what effect Grok is used on X. At the platform level, we find that Grok responds to 62% of requests, that the majority (51%) are in English, and that engagement is low, with half of Grok's responses receiving 20 or fewer views after 48 hours. We also inductively build a taxonomy of 10 roles that LLMs play in mediating social interactions and use these roles to analyze 41,735 interactions with Grok on X. We find that Grok most often serves as an information provider but, in contrast to LLM use in private one-on-one settings, also takes on roles related to dispute management, such as truth arbiter, advocate, and adversary. Finally, we characterize the population of X users who prompted Grok and find that their self-expressed interests are closely related to the roles the model assumes in the corresponding interactions. Our findings provide an initial quantitative description of human-AI interactions on X, and a broader understanding of the diverse roles that large language models might play in our online social spaces.

翻译：xAI公司的大型语言模型Grok每周在社交媒体平台X上被数百万人调用。先前关于大型语言模型使用特征的研究主要集中于私密的一对一交互场景。Grok在X平台的部署标志着与此类场景的重大差异——交互发生在公开的社交空间。本文通过系统抽样三个月的交互数据，深入探究Grok在X平台的使用方式、时机及其影响效应。在平台层面，我们发现Grok对62%的请求作出响应，其中大多数（51%）为英文请求，且用户参与度较低——半数Grok响应在48小时内仅获得20次或更少的浏览。通过归纳分析，我们构建了大型语言模型在调节社交互动中扮演的10种角色分类体系，并运用该体系对X平台上41,735次Grok交互进行解析。研究发现Grok最常充当信息提供者，但与私密一对一场景中的大型语言模型使用形成对比的是，它还承担着争议管理的相关角色，如真相仲裁者、倡导者和对抗者。最后，我们通过特征分析发现：触发Grok交互的X平台用户群体，其自我表达的兴趣偏好与模型在相应交互中承担的角色高度相关。本研究首次对X平台人机交互进行了量化描述，并为理解大型语言模型在在线社交空间中可能扮演的多元化角色提供了更广阔的视角。