Introduction to the Semantic Web


Published on

Published in: Technology, Education
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Introduction to the Semantic Web

  1. 1. The Semantic Web - a useful, usable technology? Liddy Nevile La Trobe University
  2. 2. <ul><li>The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework ( RDF ), which integrates a variety of applications using XML for syntax and URIs for naming. - W3C </li></ul>
  3. 3. <ul><li>WWW2004 Semantic Web Track and Devday Presentations Online 2004-05-26 ,The W3C Track on the Semantic Web and the Semantic Web Developers Day presentations are now online. These presentations provide a status update on the Semantic Web Activity at the W3C and highlight examples of industry adoption and novel applications using Semantic Web technologies. </li></ul><ul><li>See sw / </li></ul>
  4. 4. <ul><li>&quot;The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation. ” -- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web , Scientific American, May 2001 </li></ul>
  5. 5. A use case <ul><li>DCMI has elements, terms, schemata, as well as growing sets of documents. All these need to be managed. What happens when new terms are created, when new documents are generated? </li></ul><ul><li>Can the semantic web technology being developed make this nightmare of human management an automated task? </li></ul>
  6. 6. A better question … <ul><li>Can metadata become operational so it does some of the things that we have had to do to it in the past? </li></ul><ul><li>Instead of having to develop applications to sort and shift information about, can we get the information to do that work for us? </li></ul>
  7. 7. General Public (on the Web) Users (with middle wear/ AT / Browsers) Website Your Current Website Semantic Annotations, Automatic Fixes, Database views Engine Layer of Meaning Presentational Layer Alternative versions Untouched original
  8. 8. Before…. As see on the Web Navigation Bar made with images-only. Completely inaccessible to assistive technology. Relationship between text and form elements inaccessible to assistive technology.
  9. 9. After…(1) Meaning behind images is known Relationship between text and form elements is known Enhanced Navigation for screen readers, PDA’s and orientation As see on the Web
  10. 10. Middleware Architecture (taken from SWAP) Original HTML SWAP ML Translation rules Semantic annotations Data Base XHTML Scenario-specific transformations XHTML XHTML XHTML Original presentation Extract presentation Scenario-specific CSS Rules and transformations
  11. 11. Semantic web <ul><li>Additional layers of information </li></ul><ul><ul><li>Provide meanings of terms </li></ul></ul><ul><ul><li>Provide relationship information </li></ul></ul><ul><ul><li>Links to relevant information </li></ul></ul><ul><ul><li>Links to relevant people </li></ul></ul><ul><li>Allow software agents to manipulate this information </li></ul><ul><li>Ontology defines terms </li></ul>
  12. 12. Resource Description Framework (RDF) <ul><li>Language for semantic web </li></ul><ul><li>Not just machine readable information </li></ul><ul><li>Also machine understandable information </li></ul><ul><li>eg: </li></ul><ul><li><? xml version=&quot;1.0&quot; ?> <rdf:RDF xmlns:rdf=&quot; &quot; xmlns:s=&quot; &quot;> <rdf:Description about=&quot; &quot; bagID=&quot; D_001 &quot;> <s:Creator> Ora Lassila </s:Creator> <s:Title> Ora's Home Page </s:Title> </rdf:Description> </rdf:RDF> </li></ul>
  13. 13. Ontology <ul><li>System of concepts and relations between them: </li></ul><ul><ul><li>Table [is piece of] furniture </li></ul></ul><ul><ul><li>Arm [is part of] body </li></ul></ul><ul><ul><li>Japan [is located in] East Asia </li></ul></ul><ul><li>A method for storing and representing knowledge </li></ul>
  14. 14. EGs of types of annotations <ul><li>Meaning behind text gaps – text equivalents </li></ul><ul><li>Relationship to applications – no frames / functional equivalents </li></ul><ul><li>Relationship between text nodes and form elements - accessible forms and labels </li></ul><ul><li>Structural identification of page elements - orientation </li></ul><ul><li>Role information – this is a data, types of content </li></ul><ul><li>Concepts – implied content </li></ul><ul><li>Resolving ambiguities and relative importance – simplifications </li></ul><ul><li>Plus interpretation = communication of knowledge </li></ul>
  15. 15. Relationships and meanings <ul><li>This picture has meaning of welcome </li></ul><ul><li>This picture is a link to the home page </li></ul><ul><li>This color code implies feminine relevance </li></ul><ul><li>This list of links is similar to a main menu </li></ul><ul><li>This format is similar to a title </li></ul><ul><li>This paragraph is less important for this user group </li></ul><ul><li>The word ‘it’ refers to the table </li></ul>
  16. 16. Components <ul><li>an ontology for accessibility </li></ul><ul><li>a authoring tool for creating RDF using this ontology for specific pages </li></ul><ul><li>a user agent that renders accessible pages based on our ontology </li></ul><ul><li>a flexible testing tool </li></ul>
  17. 17. Roles and rel’ships (predicates) <ul><li>IsBlock - point to a block of links (is included in V1 of SWAP) and associates a content type </li></ul><ul><li>BelongsToBlock - associates link or section of content with a block (IsBlock) (is included in V1 of SWAP) </li></ul><ul><li>ContentType - associates a section of content or link with a content type </li></ul><ul><li>Header - points to link block header, Can also associate a block of links (sub-menu) with a parent menu, etc </li></ul><ul><li>SubmenuOf - associates a sub-menu with main menu </li></ul><ul><li>Association – Implied meaning behind the content and presentation </li></ul>
  18. 18. Properties <ul><li>Advertisement </li></ul><ul><li>Warning (less safe) </li></ul><ul><li>Off-site </li></ul><ul><li>Important </li></ul><ul><li>Less important </li></ul>
  19. 19. Annotation Based Accessibility <ul><li>Provide conditional alternate content </li></ul><ul><li>Address traditionally problematic areas in accessibility </li></ul><ul><ul><li>Interfaces for cognitive / age related disabilities </li></ul></ul><ul><ul><li>Summaries, clarifications and illustrations for these disabilities can be hidden.. </li></ul></ul><ul><li>Address emerging accessibility issues </li></ul><ul><ul><li>Inaccessible languages </li></ul></ul><ul><ul><li>Schemas can be annotated </li></ul></ul><ul><ul><li>Elements can be marked as “similar”.. </li></ul></ul>
  20. 20. What else can it do? <ul><li>Allow anyone to annotate any document with alternatives </li></ul><ul><li>Attach a user profile to alterative content </li></ul><ul><li>Concept mapping / sign and symbols </li></ul><ul><li>Remove ambiguity in language </li></ul><ul><li>Device independence </li></ul><ul><li>Knowledge systems integration </li></ul><ul><li>Support for internationalization / localization and translation …. </li></ul>
  21. 21. Quinkan Example 1 <ul><li>Translation .. service </li></ul>Tommy George inspecting red rock ochre. &quot;A lot of paintings are made in red.&quot;
  22. 22. Quinkan Example 2 <ul><li>Objects without explanation </li></ul><ul><li>How is it done? </li></ul>“ A hand stencil”
  23. 23. SVG images <ul><li><?xml version=&quot;1.0&quot; encoding=&quot;iso-8859-1&quot;?> </li></ul><ul><li><!DOCTYPE svg PUBLIC &quot;-//W3C//DTD SVG 20000303 Stylable//EN&quot; &quot;; [ <!ENTITY st0 &quot;fill-rule:nonzero;clip-rule:nonzero;stroke:#000000;stroke-miterlimit:4;&quot;> <!ENTITY font1 'font-family:&quot;Verdana&quot;;'><!ENTITY size1 &quot;font-size:24;&quot;>]> </li></ul><ul><li><svg width=&quot;690&quot; height=&quot;182&quot; viewBox=&quot;130 10 550 220&quot; xml:space=&quot;preserve&quot;> </li></ul><ul><li><g id=&quot;Ebene_x0020_1&quot; style=&quot;&st0;&quot;> </li></ul><ul><li><image width=&quot;690&quot; height=&quot;182&quot; xlink:href=&quot;data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0aHBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAC2ArIDASIAAhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/ </li></ul><ul><li>…… </li></ul><ul><li>… </g> </li></ul><ul><li>… .. </li></ul>
  24. 24. Quinkan Example 3 <ul><li>When Aboriginal people meet, they greet each other with lengthy descriptions of their identity and family connections. </li></ul><ul><li>Tom adds his photo. </li></ul><ul><li>Mary adds her photo. </li></ul><ul><li>The relationship between them is in the metadata (dc:subject and dc:description) </li></ul><ul><li>but it is not operational. </li></ul>
  25. 25. How do we represent families? <ul><li>Traditional western ‘family tree’ </li></ul><ul><ul><li>has-mother, has-father </li></ul></ul><ul><ul><li>-> has-grandmother, has-grandfather, has-sibling,... </li></ul></ul>
  26. 26. How do we represent families? <ul><li>Traditional western ‘family tree’ </li></ul><ul><ul><li>has-mother, has-father </li></ul></ul><ul><ul><li>-> has-grandmother, has-grandfather, has-sibling,... </li></ul></ul><ul><li>Start with Friend-of-a-friend (FOAF)? </li></ul>
  27. 27. Graphical cataloguing <ul><li><rdf:RDF </li></ul><ul><li>xmlns:rdf='' </li></ul><ul><li>xmlns:NS0=''> </li></ul><ul><li><rdf:Description rdf:about='#red'> </li></ul><ul><li><rdf:type rdf:resource=''/> </li></ul><ul><li></rdf:Description> </li></ul><ul><li><rdf:Description rdf:about='#A0'> </li></ul><ul><li><rdf:type rdf:resource=''/> </li></ul><ul><li><NS0:has-name rdf:resource='#TommyGeorge'/> </li></ul><ul><li></rdf:Description> </li></ul><ul><li><rdf:Description rdf:about='#AADXEVJJKH'> </li></ul><ul><li><rdf:type rdf:resource=''/> </li></ul><ul><li></rdf:Description> </li></ul><ul><li><rdf:Description rdf:about='#TommyGeorge'> </li></ul><ul><li><rdf:type rdf:resource=''/> </li></ul><ul><li></rdf:Description> </li></ul><ul><li><rdf:Description rdf:about='#r23g67b98i'> </li></ul><ul><li><rdf:type rdf:resource=''/> </li></ul><ul><li><NS0:is-same-as rdf:resource='#098734827'/> </li></ul><ul><li><NS0:is-same-as rdf:resource='#AADXEVJJKH'/> </li></ul><ul><li></rdf:Description> </li></ul><ul><li><rdf:Description rdf:about='#098734827'> </li></ul><ul><li><rdf:type rdf:resource=''/> </li></ul><ul><li></rdf:Description> </li></ul><ul><li><rdf:Description rdf:about='#pfgjner25243'> </li></ul>and lots more…..
  28. 28. <ul><li>So how do we understand the semantic web? </li></ul>
  29. 29. The drawers method
  30. 30. The filing cabinet
  31. 31. Metadata labels
  32. 32. RDF Labels
  33. 33. RDF labels for labels Has father Fred Has mother Mary Has father Fred Has mother not-Mary Has sister Jean Has half-sister Jean
  34. 34. RDF Labels
  35. 35. The Yolngu Language Project
  36. 36. Metaphors <ul><li>The intelligent links ... </li></ul><ul><li>The patchwork quilt … </li></ul><ul><li>We can find not only what we want but about what interests us … </li></ul>
  37. 37. <ul><li>Semantic Web Best Practices and Deployment Working Group (see sw / BestPractices / </li></ul>
  38. 38. SWeb Task Forces <ul><li>The following task forces are in progress: </li></ul><ul><li>OEP - Ontology Engineering and Patterns Coordinator: Deb McGuinness </li></ul><ul><li>PORT - Porting Thesaurii to RDF and OWL description Coordinator: Dan Brickley </li></ul><ul><li>WordNET description, notes toward revised description Coordinator: Aldo Gangemi </li></ul><ul><li>WRLD - World View description Coordinator: Jim Hendler </li></ul>
  39. 39. SWeb Task Forces <ul><li>The following task forces are under discussion to start: </li></ul><ul><li>VM - Vocabulary Management description Coordinator: Tom Baker </li></ul><ul><li>XSCH - XML Schema Datatypes description Coordinator: Jeremy Carroll & (open - XML Schema WG) </li></ul><ul><li>HTML - Embedding RDF in HTML </li></ul><ul><li>ADTF - Applications and Demos description Coordinators: Libby Miller, Brian McBride </li></ul>
  40. 40. SWeb Task Forces <ul><li>Other task forces that have expressions of interest from WG members include: </li></ul><ul><li>Coping with evolving ontologies </li></ul><ul><li>Links to MPEG </li></ul><ul><li>Style conventions (naming, namespaces, uri, rdf:label usage) </li></ul><ul><li>Tools index </li></ul><ul><li>Ontology Design Issues </li></ul><ul><li>Units and measures </li></ul>
  41. 41. Semantic Web Tools <ul><li>W3C Co-ordinated activity - see ( local ) </li></ul>
  42. 42. <ul><li>Thank you. </li></ul>