User Perspective

From the users point of view, the behaviors desired of a UIA are:

• Interfacing A UIA has to be effective in interfacing with the user as well as the TOS. For user interfacing, it has to keep track of the user specified goals, preferences and constraints, provide relevant information to the user, request clarifications or other information from the user and process the replies from the user. For system interfacing, the UIA has to interact with a TOS by both sending valid TOS commands to it and receiving or observing readings that the TOS produces.

• Proactivity Since the user is insulated from directly manipulating, controlling and maybe even monitoring the target TOS, much of the proactive responsiveness which would normally be the provenance of the user must be taken over by the agent. Thus, it becomes the responsibility of the agent to respond to any perturbations such as contradictory information or a difference between expected and actual outcomes, quickly and effectively. To detect such perturbations, the UIA has to keep track of the effects of the TOS commands it issues, by interpreting the readings that the TOS produces, and when such readings are not available, by confirming with the user if and when required. That is, if the TOS has the necessary sensors to observe the readings of its actions, then the agent can keep track of the effect of the TOS commands it issues, by interpreting these TOS readings; but if the TOS does not have such sensors, then the agent can rely on confirmations that it gets from the user.

• Reactivity The agent has to respond to user instructions and TOS readings in a dynamic manner. This requires that the agent be able to accept stimuli from either the user or the TOS at any time, independent of its activity at that time. For instance, for the user instruction ``Warm the pool to $85^oF$ now'', the agent has to issue ``HEAT POOL'' TOS command immediately and, when the temperature reading from TOS reaches $85^oF$ or more, the agent has to respond immediately by issuing ``STOP HEAT'' command.