Discovery of hierarchical representations for efficient planning
Fig 2
Hierarchical representations reduce the computational costs of planning.
A. Planning in the low-level graph G takes at least as many steps as actually executing the plan. All nodes and edges are thick, indicating that they must all be considered and maintained in short-term memory in order to compute the plan. B. Introducing a high-level graph H alleviates this problem. At any given time during plan execution, the agent only needs to consider the high-level path and the low-level path leading to the next cluster, recomputing the latter on-the-fly. Gray arrows indicate cluster membership. C. The hierarchy can be extended recursively, further reducing the time and memory requirements of planning.