One blackboard application might require consistency, another might allowincompatible alternatives. There must be a common understanding of the representation of the information on the blackboard, understood by all KSs. There's a tradeoff between representational expressiveness of a specialized representation shared by only a few KSs and a general repreentation understood by all. When the blackboard gets full, we must still have a way for the KSs to immediately see the information important to them. Often we have multiple or subdivided blackboards, or information is sorted alphabetically or by reference.
Efficient retrieval is also important.
The board knows what kind of event each KS is looking for, and considers it for activation whenever that kind of event occurs. Need for Control A control component seperate from the individual KSs is responsible for managing the course of problem solving. The control component doesn't share the specialities of the KS's, but looks at each KSs evaluation of its own contribution to decide which one gets to go. Incremental Solution Generation Blackboard systems are effective when there are many steps towards the solution and many potential paths involving these steps. It works opportunistically, exporing the paths most effective in solving the particular problem and can outperform a solver that uses a predetermined approach.