Blackboard

Context

An immature domain in which no closed approach to a solution is known or feasible.

Problem

No feasible deterministic solution for data transformation into high-level data structures. The domain has uncertain or approximate knowledge. The transformations can result into many alternatives.

Forces

• A complete search of the solution space is not feasible in a reasonable time

• Immature Domain

• Different algorithms that solve partial problems

• Input, as well as intermediate and final results, have different representations

• An algorithm usually works on the results of other algorithms

• Uncertain data and approximate solutions are involved

• Employing disjoint algorithms induces potential parallelism

Consequences

• Experimentation

• Support for changeability and maintainability

• Reusable knowledge sources

• Support for fault tolerance and robustness

Liabilites

• Difficulty of testing

• No good solution is guaranteed

• Difficulty of estabilishing a good control strategy

• Low Efficiency

• High devlopment effort

• No support for parallelism