Tools for DAML-Based Services, Document Templates, and Query-Answering

Intent of Work (IOW) for April 2001 through March 2002

Sponsor: Department of the Air Force

Reference: F30602-00-0579-P00001

Prof. Richard Fikes, Principal Investigator

Dr. Deborah McGuinness, Technical Program Manager

Knowledge Systems Laboratory

Computer Science Department

Stanford University

  1. DAML Language Development

KSL continues to play a leadership role in its DAML language and committee work. In the next year KSL will provide:

Our hope is that the next step after the W3C committee is formed will be to follow a path similar to that used for the dissemination of HTML and XML. The central goal is to obtain widespread adoption of the language as the standard markup language for the Semantic Web with a user community similar to the current XML user community.

  1. DAML-Enabled Web Services
  2. KSL also continues to play a leadership role in DAML Web Service markup and agent technology development. In the next year, KSL will focus on the following tasks.

    1. DAML Web Services Markup Language (DAML-S)

DAML-S is being designed for use by Web service providers to describe the capabilities of their services in semantic markup. The DAML-S description of a service will enable the service to be found by agents seeking such services, and will enable agents who are considering use of a service to determine the requirements for using the service, the results produced by the service, and the protocol for using the service.

    1. DAML-S Web Service Annotation Tool
    1. Web Service Composition, Interoperation, Execution Monitoring, and Recovery
  1. Reasoning With Knowledge Represented In DAML

The methodology we develop will be based on the idea of associating with a Web page containing DAML markup an agent that is an expert on the knowledge represented in the DAML markup on the page and that provides a set of information services based on that knowledge. We will develop an API and architecture for such agents that will support providing a query answering service using the markup on the page as its knowledge base and some or all of the content of that knowledge base in various forms such as a set of RDF statements, a KIF logical theory, an HTML document suitable for presentation on various output media, etc. We will explore the notion of extending that idea to say that the *only* thing one encounters when accessing DAML markup is such an agent, where one of the services of the agent is to provide the knowledge represented there in text as a DAML element. The agent would act like a knowledge server for the knowledge represented in DAML markup in that it could keep the content of the markup loaded or in a quickly loadable form and include a query answering and constraint checking service.

The ability to automatically reason with knowledge expressed on Web pages is a central notion in the Semantic Web vision. A reasoning capability enables answers to be determined for queries from Web sites that do not explicitly state those answers. The reasoner infers the implicit answers by using the content of the Web site and of the ontologies used by the Web site. In addition, a reasoning capability can determine whether the information expressed in semantic markup on a Web site is logically consistent with the ontologies referenced by the Web site. Such reasoning is a core capability of semantic markup that distinguishes its use from the use of XML and HTML.

The reasoning technology we are developing will provide a query answering facility that performs deductive retrieval from knowledge represented in DAML and a diagnostic facility that checks the logical consistency of such knowledge. The query answering facility can be used by any service or tool that is retrieving information from DAML markup, and the diagnostic facility can be used by any service or tool that is supporting the authoring of semantic markup. We will illustrate these potential uses by developing the query-answering agent described above for Web sites containing DAML markup and by exploiting the consistency checking reasoning in our Chimaera ontology development environment described below.

  1. Ontology Development Environment

KSL continues its migration and customization of its ontology tool environment to the DAML Language. The main areas of emphasis are in the following areas.

The intended audience for the full translator and the deep ontology environment tools are the owners of ontologies. This is a small group of specialized people like database schema owners. The lightweight tools however are aimed at the masses. The lightweight tools attempt to simulate a "Microsoft FrontPage"-like tool that allows the masses to generate syntactically valid HTML (and then analyze and maintain it from a semantic perspective). Interest in both the lightweight and heavyweight tools has been voiced from large companies such as Cisco and Daimler Chrysler, startup companies, small companies such as VerticalNet, and academic and government entities.