Towards Ontology-based harmonization of Web content standards

Transcription

1 Towards Ontology-based harmonization of Web content standards Nicola Guarino, Christopher Welty, and Christopher Partridge LADSEB/CNR Padova, Italy on sabbatical from Vassar College, Poughkeepsie, NY Abstract. The popularity and press surrounding the release of XML has created widespread interest in standards within particular communities that focus on representing content. The dream is that these standards will enable consumers and B2B systems to more accurately search information on the Web within these communities. We believe the expansiveness and diversity of the Web creates a need for a small set of standard semantic primitives that have the same meaning and interpretation across communities. Such a standard set of primitives should take into account existing efforts in ontology, and in e-commerce content standards. We are investigating existing content standards proposals for the Web, and present here a large, but by no means complete, list of these standards efforts classified by their ontological sophistication and their intent. We then propose some very preliminary notions of how these standards could be harmonized to produce a set of standard semantic primitives for describing content. 1 Introduction The popularity and press surrounding the release of XML has created widespread interest in standard tagsets within particular communities that focus on representing content. The goal of these standards is to enable consumers and B2B systems to more accurately search information on the Web within these communities. Each one of these standards efforts is being carried out in almost complete isolation from the others. Practitioners and researchers in information system and software engineering know full well that no system will function in isolation for very long. Eventually, it seems clear that these communities will require some interoperability. For example, the Automobile Network Exchange (ANX) and the Open Financial Exchange (OFX) may seem at the current time to be independent and isolated communities (indeed, they are each developing their own web standards, see below). It is not hard to imagine, however, that companies in the automobile industry will want to interact with companies in the financial industry. Certainly they do outside of the world of e-commerce, since many people get financing when they buy a car, and many car dealers get financing when they fill their lots. Unfortunately, even those communities that do recognize the eventual need for interoperability seem to believe that since their content standards are expressed in XML, they will be able to interoperate. We believe that there is a need for a set of standard semantic primitives that have the same meaning and interpretation across commu-

2 nities, and can therefore serve as a starting point in any integration or interoperation effort. Proposing a set of standard semantic primitives may sound very much like proposing a standard top-level ontology. While there are certainly similarities between the two, the primary difference is that we are working towards a very small and simple set of primitives that takes into account existing efforts in ontology, and in e-commerce content standards. This work is in the preliminary stages, at the moment we are collecting and cataloging content standardization efforts, and attempting to classify them according to a simple scheme we have devised and are evolving. In this position paper we present our classification scheme, followed by an incomplete list of efforts and how they fit into our scheme. We conclude with some brief comments on how we believe this work will impact our ultimate goal to develop a set of standard semantic primitives for the Web. 2 Classifying Standardization Efforts We have analysed a number of content standardization efforts and identified what are, for our purposes, relevant properties we wish to associate with each one. The following sections describe our classification scheme and explain the entries found in the appendix. 2.1 Main Classifications All standards efforts are classified along two principle dimensions, the semantic depth, and the domain type. Semantic Depth. There are five levels of semantic depth in our ontology, in order of increasing depth: 0. Repositories (Biztalk, EDI,...) 1. Interchange formats and protocols (XML/EDI, eco ) 2. Common data dictionaries (ISO/BSR, CALS/UDEF, Dublin Core ) 3. Thesauri (WordNet, EuroWordNet, UN/SPSC ) 4. Reference models (Meta Data Coalition, Workflow Management Coalition, Indecs ) 5. Axiomatic ontologies (CYC, DARPA/CPR, NIST/PSL ontology ) Domain Type. There are five specific types of domains that have arisen in our analysis: 1. General content standards and ontologies (WordNet, CYC, ISO/BSR, CALS/ UDEF, ) 2. Process standards (NIST/PSL ontology, DARPA/CPR, ) 3. Product standards (ISO/STEP, UN/SPSC, RosettaNet ) 4. Information media standards (Dublin Core, INDECS, CIDOC ) 5. Conceptual modeling and representation standards (UML meta-model, EPIS- TLE )

3 2.2 Other Attributes In addition to the primary classifications, and obvious attributes like acronym, name, and URL, we have also recorded certain other information to assist in understanding the standardization efforts. Meta-Content. Some standardization efforts specifically address meta-content issues, as opposed to simply describing a domain. This is basically a boolean attribute, however some efforts such as the Dublin Core deal with meta-content in such a simplistic fashion that we chose to differentiate it from others with a some value. A few efforts, such as the Basic Semantic Repository, were so vague on the issue we created another value indicating we tried to figure it out but couldn t (?). Business Content. Most efforts contained business knowledge encapsulated in the standard, while others (normally the efforts classified as having general domain specificity) attempted to be independent. This, like meta-content, is basically a boolean attribute with two possible variations. Focus. Names the domain of interest, if any, motivating the standardization effort. 3 Content Standardization Efforts The appendix contains a table listing content standardization efforts we have found that focus on e-business. We make no claims of completeness nor accuracy, the list is being compiled as a resource for ourselves and others, and will be made public on our web page shortly. Blank cells in the tables indicate that we have not yet determined a value for that attribute. A? indicates we have tried to determine a value but were unable to, usually because the web pages or other information we found was incomplete. The table shows content standardization efforts that we have classified according to the two main criteria (domain specificity and semantic depth) discussed in the previous section. 4 Towards a Standard Semantics Our intent is to study these standardization efforts, and develop a small set of semantic primitives that seem most likely to have meanings that can be agreed upon and standardized. These primitives will serve as primitive semantic tools, the way XML serves as a primitive syntactic tool, and will be described and standardized using basic notions of formal ontology [2] such as those described in [3]. Examples of likely candidates for this standardization are high-level notions such as Part [1], and Subject [4], and lower level notions such as Person and Document. Our goal will not be to create a monolithic top-level ontology that specifies one way of viewing the world, but to create a minimal set of primitives that have a crisp and agreed-upon meaning. 5 Conclusion We have presented a simple ontology for classifying content standardization efforts that organizes them along two primary dimensions: semantic depth and domain specificity,

4 and then presented a significant number of efforts in the framework of our ontology. We hope this will prove to be an important resource for content standardization efforts. We are using this resource as input to a proposal for a minimal set of standard semantic primitives that can augment the standard syntax primitives offered by the existing XML standard. References 1. Artale, A., Franconi, E., Guarino, N., and Pazzi, L Part-Whole Relations in Object- Centered Systems: an Overview. Data and Knowledge Engineering, 20(3): Elsevier. 2. Guarino, N Formal Ontology in Information Systems. In N. Guarino (ed.) Formal Ontology in Information Systems. Proceedings of FOIS'98, Trento, Italy, 6-8 June IOS Press, Amsterdam: Guarino, N., and Welty, C Identity, Unity, and Individuality: Towards a Formal Toolkit for Ontological Analysis. In, Proceedings of ECAI-2000: The European Conference on Artificial Intelligence. Available from Papers/OntologyPapers.html. 4. Welty, C. and Jenkins, J An ontology for subject. Data and Knowledge Engineering. 31(2): Elsevier.

5 Acronym AAT Table of Content Standardization Efforts Full Name Art and Architecture Thesaurus Semantic Depth Domain Type Automobile Network ANX exchange BizTalk Protocol Process CDIF CIDOC CIMI profile CWM Common Data Interchange Framework International Committee for Documentation Common Warehouse Focus Meta Bus. Thesaurus Product Art and architecture No Yes Web address shiva.pub.getty.edu/ aat_browser/ Thesaurus Product Automotive No Yes Business documents handling Yes biztalk/default.asp General Electronics Yes cdif/index.html Product Museums? Yes guide Thesaurus Product Museums No Yes Data Warehousing No? No cxml Commerce XML Protocol Process ecommerce No No DCMI EDIFACT EPISTLE FpML Dublin Core Metadata Initiative Electronic Data Interchange for Administration, Commerce and Trade European Process Industries STEP Technical Liaison Executive Financial products Markup Language Information Libraries/Web Catalogs Protocol Product ecommerce No Yes Protocol Process industry Yes Yes Finance No Yes Z39.50 Profile for Cultural Heritage Information Information home/ No Yes purl.org/dc/ epistle.htm HL7 Health Level Seven Product Healthcare Yes Yes ICE IDEF5 INDECS ISITC ISO 2789 ISO IEC ISO1087 ISO5964 MDCOIM Information & Content Exchange Integration Definition for Function ing Ontology Description Capture interoperability of data in e-commerce systems Documentation--Guidelines for the establishment and development of monolingual thesauri Metadata Registry Coalition Terminology Vocabulary Documentation and establishment of multilingual thesauri MDC Open Information Protocol Process Information International Securities Association for Institutional Trade Communication Exchange of online assets? Yes Methodologies Yes No Intellectual Property No Yes Security Industry Transactions Dictionary General Thesauri Yes No General ling Yes No Dictionary General Terminology Yes No Dictionary General Thesauri Yes No General Yes Yes No Yes ~ftp/l8/other/coalition/ Coalition.htm MOF Meta Object Facility General ling Yes NAICS North American Industry Classification System

6 Acronym NIIIP NIIIS OBI National Industrial Information Infrastructure Protocols National Industrial Information Infrastructure Process Virtual Enterprise Yes EXPRESS models Protocol Process B2B ecommerce Yes OCF Online Catalog Format Product Product Catalogs No Yes OFX Open Financial Exchange Product Financial transactions No Yes Open Buying on the Internet POSC-CAE- SAR PSL RosettaNet Petrotechnical Open Software Corporation - CAE- SAR Process Specification Language RosettaNet Catalog Interoperability Proposal Product Petroleum No Yes Process Dictionary Product Electronics Yes SWIFT S.W.I.F.T. Dictionary Product Finance transactions No Yes UDEF UML Meta model Universal Data Element Framework Universal ling Language Meta Dictionary General Business No Yes General Yes UMLS General Healthcare Yes Yes UN/SPSC Thesaurus Product Yes WfMC xcbl XML/EDI Repositories Workflow Management Coalition Table of Content Standardization Efforts Full Name XML Common Business Library Semantic Depth Process Workflow Yes Protocol Repository Domain Type Process Focus Business documents handling Meta some Bus. Yes Web address index.html