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Problem solving and reasoning

The following iterative steps occur in typical blackboard solving activities:

  1. A knowledge source makes a change to a blackboard object.
  2. Each knowledge source indicates the contribution it can make to the new solution state -- either dynamically or a priori based.
  3. A scheduler decides a focus of attention.

  1. A control module prepares the focus of attention for execution:
    1. If the focus of attention is a knowledge source -- a blackboard object is chosen to serve as its context (knowledge centred scheduling).
    2. 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).
    3. 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.

  1. The problem solving process continues until a knowledge source has indicated that it should stop:
    1. either an acceptable solution has been found, or
    2. lack of knowledge or data prohibits further action.