PRODIGY: Knowledge represented as Control Rules
Description
- Represented as first-order logic condition and a control action to be
taken when condition is met
- Condition expressed in terms of meta-predicates such a CURRENT-NODE or
CANDIDATE-NODE
- Control action indicates whether to SELECT, REJECT, or PREFER a candidate
or set of candidates
- Used to select:
- which node in search tree to expand
- which goal to work on
- which operator to apply
- which objects to use
- Increase efficiency of search, improve solution quality, and direct
search along normally avoided paths
- Have access to internal state of problem
solver, so can access any knowledge source
- May be entered by hand or acquired by learning
- May be general or domain-specific
- May be heuristic preferences or absolute selections
- Permit emulation of many search heuristics
- Casual commitment strategy relies
on presence of control rules for important decisions
Detail from PRODIGY