In this commentary I argue that although pddl2.1 is a very useful standard for the planning competition, its design does not properly consider the issue of domain modeling. Hence, I would not advocate its use in specifying planning domains outside of the context of the planning competition. Rather, the field needs to explore different approaches and grapple more directly with the problem of eff...

This study reports on an experiment in which a group of 14 American learners of Spanish as a foreign language performed two monologic production tasks with and without time for planning. Several hypotheses were tested concerning language complexity, grammatical accuracy, lexical complexity, and degree of fluency. As predicted, it was found that learners produced more complex, but not more accur...

More recently, planning based on answer set programming has been proposed as an approach towards realizing declarative planning systems. In this paper, we present the language K , which extends the declarative planning language K by action costs and provides the notion of admissible and optimal plans, which are plans whose overall action costs are within a given limit resp. minimum over all pla...