I am almost exclusively working in automated planning, one of the main disciplines of Artificial Intelligence.
I am primarily interested in Hierarchical Task Network (HTN) planning, which is a hierachical approach to planning, where tasks are refined step-wise until a primitive executable plan is obtained. Closely related is the problem class of HTN planning with task insertion (TIHTN planning), where we are also allowed to insert actions arbitrarily thus combining HTN planning with classical planning. (I also created a website on hierarchical planning.)
I'm also interested in partial order causal link (POCL) planning, a planning approach based on search in the space of plans. Here, reasoning about partially ordered actions become of major importance.
Within all these frameworks, research questions/areas that I'm mostly interested in are: