Opportunistic control of action in intelligent agents

Given its multiple goals, limited resources, and dynamic environment, an intelligent agent must decide which of many possible actions to execute at each point in time. Planning and reactive models embody two different modes of control. By contrast, a 2D space of control modes is characterized, each of which maximizes the quality of run-time behavior in the corresponding region of a 2D space of control situations. The situation space is defined by dimensions representing the predictability of the agent´s task environment and the contrast imposed by its goals. The space of control modes is defined by corresponding dimensions representing the agent´s sensitivity to run-time events and its commitment to specific actions prepared in advance. The corners of the mode space are anchored by extreme modes that an agent rarely uses: open-loop plan execution, goal-specific reactivity, dead reckoning, and reflex modes. The large interior is occupied by a space of more practical strategic control modes that modulate the balance of sensitivity and commitment for situations embodying different combinations of predictability and constraint