Figure 1

The blackboard architecture. The blackboard itself is a shared working space organized into layers. At any time during the problem solving process, it contains all the objects that have been either entered as data or inferred through the execution of knowledge sources. Knowledge sources take as input objects on one or several specific layers and write down the inferred objects on other upper layers. Among all the knowledge sources that could be applied at a given time, the controller selects the ones that will be actually executed.