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Implementation issues The following iterative steps occur in
typical blackboard solving activities: - A knowledge source
makes a change to a blackboard object. - Each knowledge source
indicates the contribution it can make to the new solution state
-- either dynamically or a priori based. - A scheduler decides a
focus of attention. - A control module prepares the focus of
attention for execution: - If the focus of attention is a
knowledge source -- a blackboard object is chosen to serve as
its context (knowledge centred scheduling). - If the focus of
attention is a blackboard object -- a knowledge source to
process that object is chosen and instantiated with the object
as its context (event centred scheduling). - If both a
blackboard object and a knowledge source are the focus of
attention an instance of the knowledge source is made ready for
execution with the object as its context. - The problem solving
process continues until a knowledge source has ind