As in Part II, it also seems appropriate to give two names
to Part III. It is officially called decision-theoretic planning, but it can also be considered as planning under uncertainty. All of the concepts in Parts
I and II avoided models of uncertainties.
Chapter 8 considered plans that can overcome some
uncertainties, but there was no explicit modeling of uncertainty.
In this part, uncertainties generally interfere with two aspects of
These two kinds of uncertainty are independent in many ways. Each has
a different effect on the planning problem.
- Predictability: Due
to uncertainties, it is not known what will happen in the future when
certain actions are applied. This means that future states are not
- Sensing: Due to
uncertainties, the current state is not necessarily known.
Information regarding the state is obtained from initial conditions,
sensors, and the memory of previously applied actions.
Steven M LaValle