Provenance Challenge: A Semantic Web Approach

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Provenance Challenge A Semantic Web Approach

• Jennifer Golbeck
• MINDSWAP
• University of Maryland, College Park

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The Semantic Web

• Ontologies are used to create schemas
• Instances (the data) can be stored anywhere
• Referenced by its URI
• Semantics of Web Ontology Language (OWL) allow
  for logical inferences on the data
• Much support for aggregation, querying, and
  browsing

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Ontologies for Workflows

• Need to represent data about
• Execution of workflow
• Execution of services
• Information about files
• Information about dependencies
• http//provenance.mindswap.org/provenance.owl

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Provenance.owl
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Web Services for Process Execution

• Web services receive inputs
• URIs of input files
• The service retrieves the files from the web,
  perform their action, and output the resulting
  files to the web (so they have a URI)
• Image/Headers/Graphics, etc
• Metadata (using the ontology) describing
• The provanance of the output files
• The service execution

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Metadata Aggregation

• Central service is pinged or spiders to collect
  metadata files from service executions
• Collection can be queried and browsed
• Metadata can be generated anywhere and stored
  anywhere
• http//provenance.mindswap.org

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Reasoning over the Data

• The big benefit of the Semantic Web
• The semantics of properties used (e.g.
  transitive, symmetric, etc) allow us to trace
  back through the provenance history easily
• Additional rules can be added to further augment
  existing semantics
• E.g. The Service Execution ancestors of a file
  are all the Service Executions that produced
  files upon which the file in question is
  dependent

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Querying with SPARQL

• SPARQL SPARQL Protocol and RDF Query Language
• Find the outputs of align_warp where the inputs
  are annotated with centerUChicago.
• PREFIX rdf lthttp//www.w3.org/1999/02/22-rdf-synt
  ax-nsgt
• PREFIX prov lthttp//provenance.mindswap.org/prove
  nance.owlgt
• PREFIX rdfs lthttp//www.w3.org/2000/01/rdf-schema
  gt
• SELECT DISTINCT ?y WHERE
• ?y provhasInputFile ?x
• provserviceUsed provalign_warp.
• ?x provannotation "centerUChicago".
• Query results are returned as RDF documents

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Thanks To

• Daniel Krech, creator of Redfoot, the package
  used on the website, and who helped get all the
  Semantic Web tool support running
• David Wang, who helped with the rules and
  visualization support