Out of oontext: Computer systems that adapt to, and learn from, context

There is a growing realization that computer systems will need to be increa singly sensitive to their context. Traditionally, hardware and software wer e conceptualized as input/output systems: systems that took input, explicit ly given to them by a human, and acted upon that input alone to produce an explicit output Now, this view is seen as being too restrictive. Smart comp uters, intelligent agent software, and digital devices of the future will h ave to operate on data that are not explicitly given to them, data that the y observe or gather for themselves. These operations may be dependent on ti me, place, weather, user preferences, or the history of interaction. In oth er words, context. But what, exactly, is context? We look at perspectives f rom software agents, sensors, and embedded devices, and a/so contrast tradi tional mathematical and formal approaches. We see how each treats the probl em of context and discuss the implications for design of context-sensitive hardware and software.