Markup languages and the semantic web
1 / 24

Markup Languages and the Semantic Web - PowerPoint PPT Presentation

  • Uploaded on

Inf 722 Fall 2007 (Gangolly) 13. Dublin Core. Metadata Elements ISO 15836:2003. Rights. Date ... Publisher. Language. Description. Source. Subject. Identifier. Creator ...

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Markup Languages and the Semantic Web' - Kelvin_Ajay

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Markup languages and the semantic web l.jpg

Markup Languages and the Semantic Web

Lecture Notes Prepared by

Jagdish S. Gangolly

Interdisciplinary Ph.D Program in Information Science

State University of New York at Albany

Inf 722 Fall 2007 (Gangolly)

Markup languages l.jpg
Markup Languages

  • Knowledge assumed:

    • HTML

      • DTD (Document Type Definition)

      • Tags

        • Format (confusion between format and other tags)

        • Structure (Too flexible, and so almost useless)

        • Content (virtually none)

      • Very poor in semantics

      • Inability to exploit latent semantics

      • Users at the mercy of browsers

      • Inflexibility in adding new tags un less blessed by browsers

Inf 722 Fall 2007 (Gangolly)

Xml i l.jpg

  • SGML, the forerunner of HTML

    • Too complex (annotated SGML standard runs over 1,000 pages

    • Too flexible

    • Little browser support

  • XML

    • Less complex and yet extensible

    • Flexible in expressing semantics

    • Browser support

Inf 722 Fall 2007 (Gangolly)

Xml ii l.jpg

  • Separation of format, content, and structure tags

    • Content: Schema

      • Rich set of data types

      • Easy to understand and implement

    • Format: XSL (XML Style-sheet language)

      • Complex and no universal browser support

      • Such support may not be crucial because of XSLT (XSL Transform) which enables HTMLize XML

    • Structure: Subsumed in content and format

    • Representing richer semantics than HTML allowed

Inf 722 Fall 2007 (Gangolly)

Xml iii l.jpg

  • Discipline enforced

  • Document Type Definition, required to specify the grammar of HTML and SGML required programmers to be familiar with one more language (EBNF - Extended Backus-Naur Formalism) in which DTDS are represented.

  • Good browser support

  • DOM (Document Object Model), SAX (Simple API for XML), and Namespaces facilitates machines to communicate and (understand) mutual data to an extent

Inf 722 Fall 2007 (Gangolly)

Semantic web l.jpg
Semantic Web

  • a mesh of information linked up in such a way as to be easily processable by machines, on a global scale. (

Inf 722 Fall 2007 (Gangolly)

Motivation l.jpg

  • Need for interchangeability of information (information sharing)

  • Need for interchangeability, translatability, uniformity of ontologies

  • Need for improving precision in retrieval

  • Need for web services based on understanding of data as well as metadata

Inf 722 Fall 2007 (Gangolly)

Semantic web components l.jpg
Semantic Web Components

  • Data

    • Structure

    • Content

    • Format

    • Ontology

  • Metadata

    • Representation Languages

    • Facility for metadata Interchange

Inf 722 Fall 2007 (Gangolly)

Slide9 l.jpg

  • Data (Semi-structured as well as structured)

    • Structure Tags: XML-Schema

    • Content Tags: XML-Schema

    • Ontology: Ontology representation languages

Inf 722 Fall 2007 (Gangolly)

Metadata i l.jpg
Metadata I

  • Representation languages based on First Order Logic

    • KIF-based Ontolingua (

    • Loom (

    • Frame-Logic (

Inf 722 Fall 2007 (Gangolly)

Metadata ii l.jpg
Metadata II

  • Languages using standardised syntax

    • Simple HTML Ontology Extensions (SHOE) (

    • XOL Ontology Exchange Language (XOL)(

    • Ontology Markup Language (OML and CKML) (Ontology Markup Language (OML and CKML)

    • Resource Description Framework Schema Language (RDFS) (

    • RiboWEB (

Inf 722 Fall 2007 (Gangolly)

Metadata iii l.jpg
Metadata III

  • OIL (Ontology Interchange Language) (

  • DAML+OIL (

  • XFML+CAMEL (eXchangeable Faceted Metadata Language + Compound term composition Algebraically-Motivated Expression Language) (

  • Good sources of information:



  • Inf 722 Fall 2007 (Gangolly)

    Dublin core l.jpg
    Dublin Core

    • Metadata ElementsISO 15836:2003

    Inf 722 Fall 2007 (Gangolly)

    Rdf http www xml com pub a 2002 01 30 daml1 html l.jpg
    RDF (

    • XML based language that allows you to define classes and properties

      <rdfs:Class rdf:ID="Product"> <rdfs:label>Product</rdfs:label> <rdfs:comment>An item sold by Super Sports Inc.</rdfs:comment> </rdfs:Class>

      <rdfs:Property rdf:ID="productNumber"> <rdfs:label>Product Number</rdfs:label> <rdfs:domain rdf:resource="#Product"/> <rdfs:range rdf:resource=""/> </rdfs:Property>

    Inf 722 Fall 2007 (Gangolly)

    Slide15 l.jpg

    • "there is a Person identified by, whose name is Eric Miller, whose email address is [email protected], and whose title is Dr."

    Inf 722 Fall 2007 (Gangolly)

    Slide16 l.jpg

    Inf 722 Fall 2007 (Gangolly)

    Slide17 l.jpg

    <?xml version="1.0"?>

    <rdf:RDF xmlns:rdf=""


    <contact:Person rdf:about="">

    <contact:fullName>Eric Miller</contact:fullName>

    <contact:mailbox rdf:resource="mailto:[email protected]"/>




    Inf 722 Fall 2007 (Gangolly)

    Daml oil i http www xml com pub a 2002 01 30 daml1 html l.jpg

    • DAML+OIL also allows you to define instances of classes and specify their properties

      <Product rdf:ID="WaterBottle"> <rdfs:label>Water Bottle</rdfs:label> <productNumber>38267</productNumber> </Product>

    • DAML+OIL allows datatyping

      <daml:DatatypeProperty rdf:ID="productNumber"> <rdfs:label>Product Number</rdfs:label> <rdfs:domain rdf:resource="#Product"/> <rdfs:range rdf:resource=""/> </daml:DatatypeProperty>

    Inf 722 Fall 2007 (Gangolly)

    Daml oil ii l.jpg

    • Provides for uniqueness, equivalence, enumerations, disjoint classes, disjoint unions of classes, non-exclusive Boolean combinations of classes, intersection of classes, sub-classing, property restrictions

    • Rich enough to model ontologies

    Inf 722 Fall 2007 (Gangolly)

    Semantic web stack of expressive power berners lee21 l.jpg
    Semantic Web Stack of Expressive Power (Berners-Lee)

    • URI (Uniform Resource Identifier)


    • Unicode


    • XML


    • RDF


    • RDF-S (RDF Schema)


    • SPARQL


    Inf 722 Fall 2007 (Gangolly)

    Slide22 l.jpg

    Inf 722 Fall 2007 (Gangolly)

    Web ontology language owl i l.jpg
    Web Ontology Language (OWL) I

    • OWL Lite supports those users primarily needing a classification hierarchy and simple constraints.

    • OWL DL supports those users who want the maximum expressiveness while retaining computational completeness (all conclusions are guaranteed to be computed) and decidability (all computations will finish in finite time).

    • OWL Full is meant for users who want maximum expressiveness and the syntactic freedom of RDF with no computational guarantees.


    Inf 722 Fall 2007 (Gangolly)

    Semantic web readings l.jpg
    Semantic Web: Readings

    • Semantic Web: Readings

    • “The Semantic Web In Breadth”, by Aaron Swartz


    • The Semantic Web: An Introduction


    Inf 722 Fall 2007 (Gangolly)