1. Thinking too much: Pathology in pathfinding
Mitja Luštrek
Jožef Stefan Institute
Department of Intelligent Systems
Slovenia
Vadim Bulitko
University of Alberta
Department of Computing Science
Canada

2. Heuristic lookahead search
Lookahead area
Current
state
Goal state
Lookahead
depth

3. Heuristic lookahead search
Known
Estimated shortest path

4. Heuristic lookahead search
Estimated best move

5. Conventional wisdom Shallower lookahead  worse move
Deeper lookahead  better move

6. Pathology Shallower lookahead  better move
Deeper lookahead  worse move

7. Pathology – history and present
Long known in two-player games [Nau 1979, Beal 1980] We investigate it in pathfinding on maps from computer games

8. We discover plenty of pathology
Come see the poster
to find out everything about it