In this paper, we propose an approach to planning in domains with cont
inuous world features. We argue that current models of world change (i
ncluding traditional planners, reactive systems, and many connectionis
t systems) implicitly adopt a discrete action assumption which preclud
es efficient reasoning about continuous world change. A formalism for
continuous world change is outlined, and an ideal continuous domain pl
anner is defined. An implemented computationally tractable approximati
on to the ideal planner is discussed and its behavior is described. Em
pirically, the implementation is shown to exhibit some of the importan
t design features of the new planning approach. Learning plays a centr
al role in this approach. With experience, accuracy is increased and p
lanning time is reduced even though the system's background knowledge
of the world is only approximate or ''plausible''. The acquired planni
ng concepts are most accurate in situations similar to the ones in whi
ch they are most exercised. Thus, the approach possesses a natural ada
ptation to systematic properties implicit in the observed distribution
of problems.