RDFUnit can apply Quality Assessment to DBpedia RML Mappings

DBpedia Mappings Quality Assessment

http://rml.io • http:// rdfunit.aksw.org

Anastasia Dimou1, Dimitris Kontokostas2, Markus Freudenberg2,

Ruben Verborgh1, Jens Lehmann2, Erik Mannens1, Sebastian Hellmann2

…WHERE { ?resource a %%C1%% ; %%P1%% ?p . }

<#Mapping>

rr:subjectMap [ rr:class dbo:MusicGenre ] ;

rr:predicateObjectMap [ rr:predicate dbo:birthPlace ].

el.dbpedia.org/

page/…

dbo:MusicGenre…

DBpedia is derived from Wikipedia using custom mappings

Domain Violation Test Case for RML mappings Domain Violation Test Case for RDF dataset

… WHERE { ?resource a dbo:MusicGenre ; dbo:birthPlace ?p. }

… WHERE {

?resource rr:predicateObjectMap ?poMap.

?poMap rr:predicate %%P1%% .

?resource rr:subjectMap ?sMap.

?sMap rr:class %%C1%%)

size time #violations

DBPedia EN 115K 11s 160

DBPedia NL 53K 6s 124

Dbpedia All 511K 32s 1,316

Quality Assessment for DBpedia RML mappings

size time #violations

DBPedia EN 62M 16h 3.2M

DBPedia NL 21M 1.5h 815K

Dbpedia All - - -

Quality Assessment for DBpedia dataset

Same violations appear repeatedly over distinct entities.

The violations are derived from mapping definitions

that specify how the RDF dataset will be generated

2AKSW, University of Leipzig1 Ghent University – imec – IDLab

el.dbpedia.org/

page/Τζαζ

dbo:MusicGenre

dbo:birthPlace el.dbpedia.org/

page/Αμερική

el.dbpedia.org/

page/Post-Rock

dbo:MusicGenre

dbo:birthPlace el.dbpedia.org/page

/Ηνωμένο_Βασίλειο

dbo:birthPlace

{{TemplateMapping

| mapToClass = MusicGenre

| mappings =

{{PropertyMapping

| templateProperty = name

| ontologyProperty = dbo:birthPlace }} }}

DBpedia custom mappings

DBpedia RML Mappings

we translated DBpedia custom mappings to RML mappings

RML mappings are expressed in RDF.

RDFUnit validation framework apply its SPARQL-based

Test Cases to RML as it applies them to RDF datasets.

faster Mappings Quality Assessment, higher quality DBpedia dataset