We argued in our Flexible Graphplan (FGP) work that the classical definition of the planning problem is too rigid to capture the full subtlety of many real problems. In light of this, we provided a new flexible definition and described a solution strategy based upon the Graphplan framework. Under this definition an action must determine how well its preconditions are met and assert a relative s...

For instance, it has been widely reported how players form meaningful – even emotional – ties to other players (e.g. Koster, 1998). Equally well-studied are phenomena such as identity play (Turkle, 1997), personality types of players (Yee, 2001), discrepancies between apparent game goals and actual player behaviour (Jakobsson & Taylor, 2003), the formation and negotiation of norms, the politics...

This paper presents a discussion of the theoretical complexity of plan recognition on the basis of an analysis of the number of explanations that any complete plan recognition algorithm must consider given various properties of the plan library. On the basis of these results it points out properties of plan libraries that make them computationally expensive. Introduction Plan recognition is a w...