Attention-focusing information is stored in a contextual schema's goal descriptions (Figure 3), that is, its descriptions of those goals that are predicted (to some extent) to occur in the situation. Each goal description contains information about how important the goal is usually in the context as well as reasons why the goal may be more or less important in this particular instantiation of the context. Goals may be more important if they advance the achievement of some other important goal, for example, and they may be less important to achieve now if some constraint or other condition in the current situation adversely impacts them. Goal descriptions also contain an estimate of the cost of achieving the goal in the context. For example, the goal ``pick up laundry'' may be achieved at relatively low cost when driving home from work, but with much higher cost when one has just boarded an airplane for another city.
Importance and cost information about each goal is combined to give the goal's priority. Goal priorities are then compared for each active goal, and the best one (or ones, if the agent can do more than one thing at a time) is selected as the current focus of attention.
Though we have yet to implement it, it would likely be a good idea if the current c-schema also could provide the agent with information about when it should re-focus attention based on changes to the situation.