Recognising Human Plans: Issues for Plan Recognition in Human-Computer Interaction

Plan recognition is the task of ascribing intentions about plans to an actor, based on observing the agent's actions or utterances. The plan recognition problem appears in three different forms: Plan recognition when the actor is aware and actively co-operating to the recognition, for example by choosing actions that make the task easier (intended plan recognition), plan recognition when the actor is unaware of or indifferent to the plan recognition process (keyhole plan recognition), or plan recognition when the actor is aware of and actively obstructs the plan recognition process (obstructed plan recognition) . I consider a specific application of plan recognition: that when a computer system ascribes intended plans to human users interacting with the system. In computer interfaces, intended plan recognition becomes an almost trivial task, similar to the task of interpreting a command language, whereas keyhole plan recognition can be hard, or even impossible, to achieve. In this thes..