Tracking Web provenance with Swoogle

1
Tracking RDF Graph Provenance using RDF Molecules
Li Ding, Tim Finin, Yun Peng and Anupam Joshi
University of Maryland, Baltimore County
Paulo Pinheiro da Silva and Deborah L.
McGuinness Stanford University
The Semantic Web knowledge onion
The role of RDF molecule in tracking provenance
RDF document level? Low recall G2, G3
missed! RDF triple level? Low precision G4 got
matched! Hence RDF Molecule is needed.
Lossless RDF graph decompositions
RDF molecule and its applications

• An RDF graph decomposition has three elements
• W, the background ontology
• d(G,W), a function that decomposes an RDF graph G
  into sub-graphs G G1, ...,Gn using W
• m(G,W), a function that merges all G's elements
  into a unified RDF graph G' using W.
• It is lossless iff ?G G m(d(G,W),W)

• An RDF molecule of an RDF graph G is the finest,
  lossless sub-graph of G given a lossless RDF
  graph decomposition (W, d, m).
• lossless - it can be used to restore graph G w/o
  adding new triples
• finest - it cannot be further decomposed into
  lossless sub-graphs

Tracking Web provenance with Swoogle
Given an RDF graph, we decompose it into RDF
moleculesand track its provenance over 680K
online RDF documentsindexed by Swoogle.

• We identified three types of lossless RDF
  decompositions
• 1. Naive decomposition
• blank nodes connect triples
• G1 gt(t1) and (t2,t3,t4,t5).
• 2. Functional decomposition
• use functional dependency semantics
• (W is empty) G1 gt (t1) and (t2,t3,t4,t5).
• (W asserts foafmbox is IFP) G1gt (t1), (t2,t5),
  (t3,t5), (t4,t5)
• 3. Heuristic decomposition
• use extend functional dependency
• (W asserts foaffirstName foafsurname together
  functionally decide a person instance) G1gt (t1),
  (t2,t3,t4), (t3,t4,t5)

Evaluating trustworthiness of aggregated FOAF
profile
With the provenance tracking service provided by
Swoogle, we may further compute trust to each
piece of fused FOAF profile.
Finding additional (partial) explanations in
Inference Web
Given an expression encoded as an RDF graph, we
may search for proofs whose conclusions imply
corresponding molecules, and then generate
additional (partial) explanations to the
expression.
Partial research support was provided by DARPA
contract F30602-00-0591and by NSF by awards
NSF-ITR-IIS-0326460 and NSF-ITR-IDM-0219649.