Environmental Engineering Reference
In-Depth Information
Update
Model
World
Model
Retrieve
Case
Goals
Execute
Plan
And
Return
Results
Case
Adapt
Case
Evaluate
Fig. 5.6.
Case-based planning
case may not be retrieved for examination and the knowledge it represents
may be lost. The system will have to start the planning with a less optimal
case. If the indexing is too loose, a large number of inappropriate cases will
be supplied and each will have to be examined and eliminated. This makes
the resulting system slower and less responsive. How to index the cases is a
central problem in case-based systems, and in a real sense, can determine its
success.
The second diculty is the reasoning component of a case-based planner.
This component is responsible for determining whether the plan will work
and repairing it if the plan can be repaired. Ultimately, if no plan is similar
to the current situation, the reasoning component must create a whole new
plan. These are dicult components to construct.
Many case-based planners use a conventional symbolic or a model-based
planner as the reasoning component of the case-based planner. The advantage
to this approach is that the resulting system has all of the capabilities of the
conventional symbolic or a model-based planner with a case-based planner's
ability to learn new cases. In effect, the case-based database generated is used
to cache the knowledge of the conventional system. This makes the resulting
system more responsive over time.
