Paper III Planning with Abstraction Hierarchies can be Exponentially Less Efficient
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by Christer Backstrom, Peter Jonsson
ftp://ftp.ida.liu.se/pub/labs/tosca/people/petej/paper3.ps.gz
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Abstract:
It is well-known that state abstraction can speed up planning exponentially, under ideal conditions. We extend this finding---showing that state abstraction may likewise slow down planning exponentially, and even result in generating an exponentially longer solution than necessary. This phenomenon can occur for abstraction hierarchies which are generated automatically by the Alpine and Highpoint algorithms. We further show that there is little hope of any drastic improvement upon these algorithms---it is computationally difficult to generate abstraction hierarchies which allow finding good approximations of optimal plans.
Citations
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| 150 | Automatically generating abstractions for planning – Knoblock - 1994 |
| 69 | Complexity results for SAS + planning – Bäckström, Nebel - 1995 |
| 63 | Search reduction in hierarchical problem solving – Knoblock - 1991 |
| 56 | ABTWEAK: Abstracting a nonlinear, least commitment planner – Yang, Tenenberg - 1990 |
| 52 | Downward refinement and the efficiency of hierarchical problem solving – Bacchus, Yang - 1994 |
| 37 | Expressive equivalence of planning formalisms – Backstrom - 1995 |
