Wide and Deep Structures
Wide: Many alternative actions, each simple.
+: few decisions to make after top level choice
- : which action to choose?
Narrow: Small number of alternatives leading to a small number of alternatives.
+: not a lot of "thinking needed at each level (little planning)
- : may need to back up
Wide and Deep: Very difficult to traverse efficiently; requires much planning and often requires look-ahead and back-up.
- Convert wide & deep structures to narrow ones with appropriate use of constraints.