Classes of search:

  • Discrete vs. Continuous
  • With/without gradient

Discrete search:

  • Mapping the search for a plan onto graph search
    • States -> Nodes, Actions -> edges, Plans -> paths
    • Plan space planning
  • BFS/DFS
    • Search as queue stack entry
      • difference from wind/unwind DFS
    • Trees vs graphs (cycle detection)
    • Search complexity
      • See costs Russel and Novig pp 81
      • Costs in a constrained space (e.g. on a plane)
  • Problem complexity
    • Overconstrained, underconstrained, "edge of chaos"

Speeding up search:

  • Iterative deepening
  • Island
    • forward/backward search
  • Macros
    • Small World Graphs
    • Breadth/Depth trade off
    • Bias for 'likely' searches
    • Path out of local minima
  • Pruning
  • Abstraction
    • Re-representation
  • Add a Heuristic