Expert systems perform well due to a large knowledge base and heuristics.
Heuristics guide systems towards plausible paths and away from implausible ones.
Questions addressed:
What is the source of heuristics' power?
How do new heuristics originate?
Source of Power
Heuristics' power derives from regularity and continuity.
Useful heuristics in similar situations suggest a continuity in their application.
The concept of APPROPRIATENESS(Action, Situation) holds, suggesting action appropriateness is continuous.
Observability: Necessary data must be gathered to evaluate heuristics.
Continuity: Abrupt changes in the world may invalidate heuristics.
Stability: Rapid changes can shorten the lifespan of a heuristic.
Origin of Heuristics
Specialization: Adapting general heuristics for specific situations.
Generalization: Extending specific heuristics to broader applications.
Analogy: Drawing parallels between similar situations.
Empirical experiments with AM and EURISKO programs favor analogy.
Other Heuretics Issues
Impact of individual heuristics on searches has been covered in other works.
Combining advice from multiple heuristics is complex but crucial for expert systems.
Heuretics as a field of knowledge includes defining and understanding heuristics' role and creation.
AM Program: Concept Discovery
AM explores mathematical concepts through heuristics.
Discovered important concepts and conjectures by following heuristic rules.
Heuristics implicitly define a search space rather than explicitly.
EURISKO: Heuristic Discovery
EURISKO extends AM by discovering new heuristics.
Meta-heuristics operate on heuristics themselves, not distinguished from domain heuristics.
Successful application of meta-heuristics led to powerful results.
Theories of Heuristics
Zero-th Order Theory: Heuristics assume continuity and time-invariance.
First-order Theory: Zero-th order theory as a useful fiction.
Second-order Corrections: Adapt heuristics as new domains and situations arise.
Graphical Representations
Power Curves: Utility of a heuristic as a function of task domain.
Specialization and Generalization: Can refine or broaden heuristics' applicability.
Practical Application and Experiments
EURISKO's application in different domains: games, programming, and VLSI design.
Leading to unique discoveries such as optimized fleet designs and circuit layouts.
Conclusion
Heuristics derive power from continuity and are crucial guides in problem-solving.
The field of Heuretics offers insights for constructing better expert systems by understanding and automating heuristics creation and application.
Acknowledgments
Contributions and support from various researchers and institutions are acknowledged, highlighting collaborative efforts in advancing heuristic research.