Very recently, the well-known concept of landmarks has been adapted from the classical planning setting to hierarchical planning. It was shown how a pre-processing step that extracts local landmarks from a planning domain and problem description can be used in order to prune the search space that is to be explored before the actual search is performed. This pruning technique eliminates all bran...

We examined the role of verbal mediation in planning performance of English-Spanish-speaking bilingual children and monolingual English-speaking children, between the ages of 9 and 12 years. To measure planning, children were administered the Tower of London (ToL) task. In a dual-task paradigm, children completed ToL problems under three conditions: with no secondary task (baseline), with artic...

One drawback of Hierarchical Task Network (HTN) planning is the difficulty of providing complete domain knowledge, i.e., a complete and correct set of HTN methods for every task. To provide a principled way to overcome this difficulty, we define a simple formalism that extends classical planning to include problem decomposition using methods, and a planning algorithm based on this formalism. In...

This paper proposes a goal recognition and planning algorithm, HTN-GRP-PO, to enable intelligent assistant agents to recognize older adults’ goals and reason about desired further steps. It will be used in a larger system aimed to help older adults with cognitive impairments to accomplish activities of daily living independently. The algorithm addresses issues including partial observability du...

The latest world-championship competition for computer bridge programs was the Baron Barclay World Bridge Computer Challenge, hosted in July 1997 by the American Contract Bridge League. As reported in The New York Times and The Washington Post, the competition’s winner was a new version of Great Game Products’ Bridge Baron program. This version, Bridge Baron 8, has since gone on the market; and...

Detecting interactions and resolving conflicts is one of the key issues for generative planning systems. Hierarchical Task Network (HTN) planning systems use critics for this purpose. Critics have provided extra efficiency and flexibility to HTN planning systems, but their procedural –and sometimes domain-specific – nature has not been amenable to analytical studies. As a result, little work is...

This paper reports on the development of a planning system for an important industrial planning problem. This planner, which is one of the modules in an integrated design-and-planning system called EDAPS, provides an integrated approach to process planning in both the electronic and mechanical domains, specifically in the manufaeture of microwave transmit-receive O/R) modules. Our planner is ba...

SHOP (Simple Hierarchical Ordered Planner) is a domain-independent H T N planning system with the following characteristics. • SHOP plans for tasks in the same order that they will later be executed. This avoids some goalinteraction issues that arise in other HTN planners, so that the planning algorithm is relatively simple. • Since SHOP knows the complete world-state at each step of the planni...

Hierarchical Task Networks (HTNs) are a common model for encoding knowledge about planning domains in the form of task decompositions. We present a novel algorithm that uses invariant analysis to construct an HTN from the PDDL description of a planning domain and a single representative instance. The algorithm defines two types of composite tasks that interact to achieve the goal of a planning ...

This paper is focused on how a general-purpose hierarchical planning representation, based on the HTN paradigm, can be used to support the representation of oncology treatment protocols. The planning algorithm used is a temporally extended HTN planning process capable of interpreting such representation and generating oncology treatment plans that have been proven to support clinical decisions ...