1. Knowledge Provenance in Semantic Wikis Li Ding, Jie Bao, and Deborah McGuinness Tetherless World Constellation, Rensselaer Polytechnic Institute Troy, NY USA Presented at AGU 2008 Fall Meeting 15–19 December 2008, San Francisco, California

2. Emerging Web Semantics Web 1.0: online text Web 2.0: collaborative online text Web 3.0: collaborative online knowledge Web 1.0 Web 2.0 Web 3.0 Collaborative Authoring Structure and Semantics Preservation

3. Motivation Question What has been done to my homepage? Existing approaches –Internet Archive: “when” –Wiki history: “when”, “who” In Semantic Wiki –Represent changes –Query changes

4. Semantic History Automatically convert Wiki History to Knowledge Provenance interlingua – PML (Proof Markup Language). This links semantic web data to information about where it came from. We provided triple level granularity for knowledge provenance in Semantic Media Wiki We support semantic queries over knowledge provenance as well as content

5. Encoding Wiki History Using PML Version 2 of Page A Version 1 of Page A InferenceStep X NodeSet A1 NodeSet A2 hasConclusion hasAntecedent isConsequentOf User:Joe ex:Revision 17:17, October 22, 2008 hasInferenceEngine hasInferenceRule hasCreationDatatime

6. 6 Knowledge Provenance Interlingua PML1 was introduced in 2002 –It has been used in multiple contexts ranging from explaining theorem provers to text analytics to machine learning. –It was specified as a single ontology PML2 improves PML1 by –Adopting a modular design: splitting the original ontology into three pieces: provenance, justification, and trust This improves reusability, particularly for applications that only need certain explanation aspects, such as provenance or trust. –Enhancing explanation vocabulary and structure Adding new concepts, e.g. information Refining explanation structure

7. 7 PML Provenance Ontology Scope: annotating provenance metadata Highlights –Information –Source Hierarchy –Source Usage

8. Initial Results (cur) (last) 17:17, October 22, 2008 Li (Talk | contribs | block) (420 bytes) (rollback | undo)last17:17, October 22, 2008LiTalkcontribsblockrollbackundo (cur) (last) 20:42, August 24, 2008 Baojie (Talk | contribs | block) (345 bytes) (undo)curlast20:42, August 24, 2008BaojieTalkcontribsblockundo (cur) (last) 23:44, August 15, 2008 Baojie (Talk | contribs | block) (331 bytes) (undo)curlast23:44, August 15, 2008BaojieTalkcontribsblockundo

9. Wiki Page “interval t1”Wiki Page “Triple 1”Wiki Page “DLM” Ongoing Work SMW History and Temporal RDF tw:DLM Deborah Triple 1 foaf:firstName Interval t1 begin-datetime end-datetime 2008-11-12 2008-11-14 interval rdf:subject rdf:predicate rdf:object Referring RDF triple via Reification integrating temporal data within RDF Claudio Gutiérrez, Carlos A. Hurtado, Alejandro A. Vaisman - Temporal RDF. In ESWC pp. 93-107, 2005Temporal RDF.

10. Ongoing Work Semantic History Computation PO1PO2PO3(triple, r_add, r_del) R1X(po1,r1,null) R2X(po1,r1,t2) (po2,r2, null) R3XX(po1,r3,null) R4XX(po1,r3,t4) (po3,r4,null) R5XX(po1,r5,null) (po2.r2,r5) R6X(po1,r5,r6) (po2,r6,null )(po3,r4,r6) R7X(po1,r7,null) (po2,r6,r7) Rn Change of an RDF wiki page POi:Property and object, Ri: for revision id. Space complexity DELTA O(m)<= DELTA <=O(m*n) m: # of triples n: # of revisions Depends on change rate Triple/revision Alternative is bitmap bitmap delta non rdf:type (smw_rels2 ) S_id, P_id, O_id, rev_id_add, rev_id_del Rev_id, rev_page, author, timestamp Revision Table rdf:type (smw_inst2) S_id, O_id, rev_id_add, rev_id_del Link table Rev_id, => linked template_page_id

11. Potential applications Computing Trust using History Trust in fragments detected by analyzing revision history (who edited which fragment) The lighter color corresponds to low trust

12. Conclusion and Future Work We have exposed wiki history information about Semantic Web data using the PML Knowledge Provenance Interlingua PML-based wiki history improves linking and access to Semantic Media Wiki data We adopted a Temporal RDF approach which is compatible with Semantic Query capabilities offered by Semantic Media Wiki The next version of Semantic history will implement Temporal RDF in SMW