Aidan Hogan, Antoine Zimmermann, Jürgen Umbrich, Axel Polleres, Stefan Decker Presented by Joseph Park SCALABLE AND DISTRIBUTED METHODS FOR ENTITY MATCHING, CONSOLIDATION AND DISAMBIGUATION OVER LINKED DATA CORPORA

 Linked Data best practices:  Use URIs as names for things (not just documents)  Make those URIs dereferenceable via HTTP  Return useful and relevant RDF content upon lookup of those URIs  Include links to other datasets  Linked Open Data project  Goal of providing dereferenceable machine readable data in RDF  Emphasis on reuse of URIs and inter-linkage between remote datasets  Web of Data  30 billion published RDF triples INTRODUCTION

 Focus on finding equivalent entities  E.g. people, places, musicians, proteins  Two entities are equivalent if they are coreferent  Interest in identifying coreferences and merge knowledge contributions provided by distinct parties (consolidation) AIMS & GOALS

 owl:sameAs  A core OWL property that defines equivalences between individuals  Two individuals related by owl:sameAs are coreferent  Inferring new owl:sameAs relations:  Inverse-functional properties (e.g :biologicalMotherOf)  Functional properties (e.g :hasBiologicalMother)  Cardinality and max-cardinality restrictions OWL:SAMEAS

CONSTRAINTS TO OWL:SAMEAS

 billion quadruples  Crawled from million web documents  billion are unique  947 million are unique triples  9 machines linked by Gigabit ethernet EXPERIMENT

 Extracted million raw owl:sameAs quadruples  Only 3.77 million unique triples  1000 randomly chosen pairs hand-checked  Trivially same (661 times)  Same (301 times)  Different (28 times)  Unclear (10 times) BASELINE – OWL:SAMEAS

 No documents used owl:maxQualifiedCardinality  434 functional properties  57 inverse-functional properties  109 cardinality restrictions with a value of 1  million memberships of inverse-functional properties  million asserted  million memberships of functional properties  1.17 million asserted  2.56 million cardinality triples  533 thousand asserted CONSTRAINT COUNTS

 Zero owl:sameAs inferences through cardinality rules  thousand owl:sameAs through functional-property reasoning  8.7 million owl:sameAs through inverse-functional-property reasoning  Resulted in a total of million owl:sameAs statements REASONING USING CONSTRAINTS

 From the million owl:sameAs quadruples  1000 randomly chosen and hand-checked:  Trivially same (145 times)  Same (823 times)  Different (23 times)  Unclear (9 times) RESULTS FROM CONSTRAINTS

 Entity concurrence—sharing of outlinks, inlinks, and attribute values  Higher score means more discriminating shared characteristics STATISTICAL CONCURRENCE

RUNNING EXAMPLE

 Observed cardinality (e.g. Card_G_ex (foaf:maker; dblp:AliceB10) = 2)  Observed inverse-cardinality (e.g. ICard_G_ex (foaf:gender; "female") = 2)  Average inverse-cardinality (e.g. AIC_G_ex (foaf:gender) = 1.5)  Can also be viewed as average non-zero cardinalities  For example, foaf:gender; 1 for “male”, 2 for “female” QUANTIFYING CONCURRENCE

ADJUSTED AVERAGE INVERSE- CARDINALITY

CONCURRENCE COEFFICIENTS

COEFFICIENT EXAMPLE

AGGREGATED CONCURRENCE SCORE

 Average cardinality of about 1.5  Average inverse-cardinality of about 2.64  Total of million weighted concurrence pairs  Mean concurrence weight of about  Highly concurring entities were in many cases not coreferent RESULTS FROM CONCURRENCE

EXAMPLE OF CONCURRENCE