Inference Algorithms
Basic Goal for Inference
All rules have the basic format:
If
condition
Then
Conclusion
Want to interpret conditions with current data
When current data make
condition
true, then know corresponding
Conclusion
Want to keep making inferences until know enough about desired results
Can think of reasoning as giving a chain from original data to results
Two Basic Approaches for Reasoning
Forward Chaining
Work left to right in diagram, from known data toward results
Apply as many rules as you can
Reach as many conclusions as possible
Stop when a desired result found
OR
Stop when you cannot infer any more
Backward Chaining
Work right to left in diagram, from possible results toward known data
Look at desired result variable(s)
Determine what rules might allow you to conclude result
Identify hypotheses that would allow rule to apply
If data known, determine if conditions for rule met
If data not known, determine what rules allow data to be inferred
created May 13, 2003
last revised May 13, 2003
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