Concept Modeling on Semantic Wiki


Published on

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

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

No notes for slide

Concept Modeling on Semantic Wiki

  1. 1. Concept Modeling on Semantic Wiki Presented by Jie Bao, RPI [email_address] Joint work with Li Ding and Zhenning Shuangguan Nov 22, 2008
  2. 2. SMW and me <ul><li>For research </li></ul><ul><ul><li>TW group portal wiki-master </li></ul></ul><ul><ul><li>Testbed for ideas: semantic history, privacy-preserving reasoning, integrity constraint, close world reasoning </li></ul></ul><ul><li>For fun and daily life </li></ul><ul><ul><li>Blog </li></ul></ul><ul><ul><li>Time management (To-do list, issue tracker, calender) </li></ul></ul><ul><ul><li>Document everything (emails, papers, drafts,…) </li></ul></ul>/14
  3. 3. Outline <ul><li>1. A formalization of SMW </li></ul><ul><ul><li>The modeling language (SMW-ML) </li></ul></ul><ul><ul><li>The query language (SMW-QL) </li></ul></ul><ul><li>2. Template-based Rule Modeling </li></ul><ul><li>3. OWL Meta Modeling (will be presented by Zhenning Shuangguan) </li></ul>
  4. 4. 1. Formalization of SMW <ul><li>Why it matters? It </li></ul><ul><li>Gives a better understanding on SMW’s </li></ul><ul><ul><li>potentials (what it can do) and </li></ul></ul><ul><ul><li>limitations (what it can not do) </li></ul></ul><ul><li>Allows evaluation of implementation, e.g., soundness and completeness </li></ul><ul><li>Promotes community-wide adoption, e.g., on multiple DB platforms. </li></ul>
  5. 5. Modeling language (SMW-ML) <ul><li>Syntax </li></ul>
  6. 6. Modeling language (SMW-ML) <ul><li>Semantics: a variation of the RDF semantics </li></ul><ul><ul><li>Resources can only be local wiki pages </li></ul></ul><ul><ul><li>N-ary property supported </li></ul></ul><ul><ul><li>No domain, range, blank node, collection and list </li></ul></ul><ul><ul><li>Classes and properties are disjoint </li></ul></ul><ul><ul><li>Allow punning between classes and individuals </li></ul></ul><ul><li>Details in [Bao & Ding, 2008] </li></ul>
  7. 7. Modeling language (SMW-ML) <ul><li>Entailment rules (sound and complete) </li></ul>
  8. 8. Query Language (SMW-QL) <ul><li>Syntax in BNF </li></ul>
  9. 9. Query Language (SMW-QL) <ul><li>Some observations </li></ul><ul><ul><li>Subquery can allow “punning” of class & ind., e.g., </li></ul></ul><ul><ul><ul><li>[[Has topic::<q>[[Category:Wiki]]</q>]] </li></ul></ul></ul><ul><ul><ul><li>[[Has topic::Category:Wiki]] </li></ul></ul></ul><ul><ul><li>Selection : </li></ul></ul><ul><ul><ul><li>top level is in Conjunctive Normal Form (CNF), e.g., (A and B) or (C and D) </li></ul></ul></ul><ul><ul><li>“ Concept ” pages: </li></ul></ul><ul><ul><ul><li>Are wiki “views” – may be tricky, e.g., concept containment, or cyclic definition. </li></ul></ul></ul>
  10. 10. Query Language (SMW-QL) <ul><li>Semantics: by translating into logic programs (LP) </li></ul><ul><ul><li>E.g., Husband(x) :- Man(x), marriesTo(x,y) </li></ul></ul><ul><li>Why doing so? </li></ul><ul><ul><li>Have a precise understanding of what a query means </li></ul></ul><ul><ul><ul><li>E.g., can a “concept” page be a subclass of a “category” page? </li></ul></ul></ul><ul><ul><li>Formal foundation for query answering, </li></ul></ul><ul><ul><ul><li>E.g., will the answer set always be unique? </li></ul></ul></ul><ul><ul><li>Better position for future extensions, </li></ul></ul><ul><ul><ul><li>E.g., adding classical negation and negation-as-failure. </li></ul></ul></ul>
  11. 11. Query Language (SMW-QL) <ul><li>Semantics: by translating into logic programs (LP) </li></ul><ul><ul><li>Minimal Herbrand model semantics </li></ul></ul><ul><ul><li>Closed world assumption (why?) </li></ul></ul><ul><ul><li>Details in [Bao & Ding, 2008] </li></ul></ul><ul><li>Example </li></ul>{{#ask: [[Category:Graduate Student]] [[Has affiliation::RPI]] |?Hobby }} Q(x,y) :- L(x), Hobby(x,y); L(x) :- A1(x), A2(x); A1(x) :- Graduate Student(x); A2(x) :- Has affliation(x,RPI);
  12. 12. 2. Rule Modeling <ul><li>Example: Template-based “Domain” inference </li></ul><ul><ul><li>{{#vardefine:value|{{#ask: </li></ul></ul><ul><ul><li>[[:{{FULLPAGENAME}}]] </li></ul></ul><ul><ul><li>|?{{{1}}}= </li></ul></ul><ul><ul><li>|mainlabel=- </li></ul></ul><ul><ul><li>|format=list </li></ul></ul><ul><ul><li>|link=none </li></ul></ul><ul><ul><li>}} }} </li></ul></ul><ul><ul><li>{{#if:{{#var:value}}|[[Category:{{{2}}}]]}} </li></ul></ul><ul><ul><li>Usage: {{Rule:Domain|hasAuthor|Document}} </li></ul></ul>“ Rule:Entailment”
  13. 13. 2. Rule Modeling: Example <ul><li> </li></ul>/14
  14. 14. 2. Rule Modeling <ul><li>Simplicity – rule as page, easy to design, easy to use </li></ul><ul><li>Scalability </li></ul><ul><ul><li>Each page can selectively turn on/off rule inference </li></ul></ul><ul><ul><li>Do not enforce completeness (which does not always matter on wiki) </li></ul></ul><ul><li>Flexibility </li></ul><ul><ul><li>Client-sided controllable </li></ul></ul><ul><ul><li>Highly extensible (rules can be added on the fly) </li></ul></ul><ul><li>Expressivity: way beyond OWL. </li></ul><ul><ul><li>Yet always terminates (due to incompleteness) </li></ul></ul>
  15. 15. Ongoing work <ul><li>Design Patterns on SMW: relational modeling, OO -modeling, advanced rule modeling </li></ul><ul><ul><li>Help to bridge the gap between non-SW developer and SW technologies </li></ul></ul><ul><ul><li>On-the-fly, client side expressivity extensions to basic semantic wikis, e.g., OWL-RL/SWRL/RIF support </li></ul></ul><ul><ul><li>Reusable libraries </li></ul></ul><ul><li>Extensions on integrity constraint </li></ul><ul><li>Ontology Meta Modeling on SMW </li></ul><ul><ul><li>OWL and OWL 2 </li></ul></ul><ul><ul><li>First Order Logic </li></ul></ul>
  16. 16. Questions? <ul><li>Reference </li></ul><ul><li>Jie Bao and Li Ding (2008) Knowledge Representation and Query in Semantic Wikis: A Formal Study. Tetherless World Constellation Technical Report. </li></ul>
  17. 17. Backup
  18. 18. Query Language (SMW-QL) Semantics: by translating into logic programs (LP)