ABSTRACT

Conversational interaction involves continual testing for evidence of common ground, and coordinated effort to enhance common ground. Common ground is unproblematic in face-to-face interactions because such a wide variety of situational elements contribute to it, and the work that people do to maintain common ground is so well integrated into habits and conventions of interaction. Activities are longer term endeavors directed at meaningful goals like “designing the layout of a town park”. Longer term activity entails top-down goal decomposition, nonlinear development of partially-ordered plan fragments, interleaving of planning, acting, and evaluation, and opportunistic plan revision. It involves coordinating and carrying out different types of task components, such as assigning roles, making decisions, negotiating, prioritizing, and so forth. Contemporary user interfaces support collaborative awareness through explicit notifications—requests for chat, email alerts. However, explicit messaging is problematic for supporting activity awareness: Activities are multifaceted and continuing, not simple and ephemeral like presence and action.