Judea Pearl on planning under uncertainty

(Pearl, 1994)

Probabilistic methods, especially those based on graphical models, have proven useful in tasks of prediction, abduction and belief revision.

In planning, however, they are less popular, partly due to the unsettled, strange relationship between probability and actions. In principle, actions are not part of standard probability theory, and understandably so: probabilities capture normal relationships in the world, while actions represent interventions that perturb those relationships.

~Judea Pearl