LTML - A Language for Representation Semantic Web Service Workflow Procedures

Keywords: insider threat detection, network security, plan recognition

Abstract: The Learnable Task Modeling Language (LTML) was developed by combining features of OWL, OWL-S, and PDDL, using a more compact andbreadable syntax than OWL/RDF to create human readable representations of webvservice procedures and hierarchical task models. Our goal was in part to develop a more robust and developer-friendly language based on the principles and design that led to OWL-S and demonstrate that such a language also provided the basis for developing tools that could learn web service procedures by demonstration. LTML’s initial and driving use is as an interlingua for the learning and procedure execution components of POIROT, a system that learns web service workflow procedures from ‘observations’ of one or a small number of semantic web service traces. The LTML language uses an s-expression based syntax for improved readability but has parsers and generators that translate the surface forms into RDF for storage in a SESAME triple store implementing POIROT’s internal blackboard. All language elements are grounded in a set of OWL ontologies. The language encompasses and extends coverage of the OWL-S process and grounding models, and introduces elements to support sets of hierarchical task methods indexed by goals, semantic execution traces, and internal tasks and learning goals. This short paper gives an overview of LTML and describes the areas where LTML diverges from or extends OWL-S and PDDL.