Présentation at Stanford logic lab in August 2009 about data integration and linked-data

1. Structured data interoperability on the Web
Fran¸ois Scharffe
c
INRIA Grenoble Rhone-Alpes, France
August 19, 2009
Stanford Logic Group

2. Introduction
The Web of data/Semantic Web is the future of structured
data !
I’ll talk about. . .
structured data
convergence of structured data extraction and structured data
publication (SW and linked-data)
Interoperability in the Web of data: issues, research and
achievments
I’ll suppose that. . .
You have a relational database approach to structured data
You know about the Web
You’ve heard about the semantic Web: RDF, OWL, SPARQL

3. Structured data and the Web
Structured data is the future of the Web
Many ongoing research aiming to extract structured data from
the Web
Deep Web, spreadsheets, forms
Fusion tables
Effort to provide formalisms, standards and tools to publish
structured data and vocabularies: Semantic Web and
linked-data
RDF, OWL, RDFa, RIF
Semantic Wiki

4. The web of Data and the open linked data project
Publish vocabularies
useful Web ontologies
Publish data
RDF
dereferenceable URIs
SPARQL endpoints
Link to existing data

5. Linked data cloud
http://www4.wiwiss.fu-berlin.de/bizer/pub/lod-datasets 2009-03-
05 colored.png

6. Interoperability issues
Vocabs Vocabularies should be reused, but anyone is free to provide its
own
Any published data sources might use its own schema as an
ontology
Results in many ontologies/vocabularies available and the need
to connect them
Data Even when a same ontology is used, if two data-sources are
published, they might contain equivalent resources
Need to interconnect these resources

7. Interconnecting vocabularies
Ontology matching and alignment is the key to issue one:
Matching algorithms
GUIs
alignment representation
patterns
mediators
Results: Alignment API and server, Ontomap, OAEI,
Alignment patterns language
Data linkage is the key to issue 2
Matching algorithms
Link specification languages
Linksets
Results: Silk, Knofuss, RDF-AI, VOID

8. Linking Data
Class 4 Class 3 Class 1 Class 2 Class 5
rdf:type
rdf:type rdf:type rdf:type
rdf:type rdf:type rdf:type
G1 G2
r1-1
r2-5
r2-1
r1-4 r1-3
r2-2
r1-2

9. Linking Data
G1 A G2
c1
r1-1
r2-5
r2-1
r1-4 r1-3
r2-2
r1-2
c2

10. Linking Data
Graphs Alignment Fused Graph
Linkset
Graphs Graph Alignment Graph Fused Graph
Parameters Parameters Parameters Parameters Linkset
Output Output Output Output
Input Input Input Input
Fusion
Pre-processing Matching Post-processing
Interlink
RDF file SPARQL Endpoint

11. Aligning Vocabularies
Class Class
Attribute Relation
Relation Correspondence
Class Attribute Attribute
Class Correspondence
Val1 Att1 Value
Val2 Att2 Transformation
Concatenation
Val3 Att3
RCA-A concat
Pattern Value
http://.../francois vc:VCard
foaf:Person http://.../francois
Attribute Relation
vc:name vc:name Correspondence
Class Attribute
_:bn01
foaf:name foaf:name
vc:N Correspondence
"Scharffe" vc:family-name Value
"François" Transformation value
vc:given-name "François Vincent
Concatenation Alfred Scharffe"
"Vincent Alfred" vc:additional-name
RCA-A concat
Pattern

12. Alignment representation
vcard:family-name a align:Property;
align:bind-with "?x".
vcard:given-name a align:Property;
align:bind-with "?y".
vcard:additional-name a align:Property;
align:bind-with "?z".
foaf:name a align:Property.
:property-group a align:Property;
or [
align:item vcard:family-name;
align:item vcard:given-name;
align:item vcard:additional-name.
].
align:transf [
align:transf-id transf:concat;
align:transf-param "?x ?y ?z".
].
:foaf-vcard-names a align:Cell;
align:entity1 :property-group;
align:entity2 foaf:name.

13. Using alignments
Matcher
produces
FOAF Alignment vCard
in
us
d-
used-in
Design Time
ed
use
-in
Run Time
FOAF Instance Mediated
SW Pipe
to be mediated vCard Instance
uses
SPARQL++
Reasoner

14. Conclusion
The data representation is there
Data integration works through owl:sameAs
Vocabularies integration works though there is no standard
representation
Where is the killer app ?