Probability
Probability theory is a mathematically rigorous way of modeling
uncertainty in the world. It should be noted that the probability values
that are assigned by a human or autonomous system to various events may
be subjective, based on faulty assumptions, estimated poorly, and
otherwise incorrect. However, probability theory describes
mathematically sound ways to manipulate probabilities, which are
guaranteed to lead to accurate predictions as long as the base
assumptions are accurate.
http://motion.pratt.duke.edu/RoboticSystems/Probability.html