Recently, RDF validation as a research field gained speed due to common needs of data practitioners. A typical example is the library domain that co-developed and adopted Linked Data principles very early. Although, there are multiple constraint languages (having different syntaxes and semantics) which can be used to express RDF constraints such as cardinality restrictions, there is no constraint language which can be seen as the standard. The five most promising ones on being the standard are Description Set Profiles (DSP), Resource Shapes (ReSh), Shape Expressions (ShEx), the SPARQL Inferencing Notation (SPIN), and the Web Ontology Language (OWL 2). SPARQL is generally seen as the method of choice to validate RDF data according to certain constraints. We use SPIN, a SPARQL-based way to formulate and check constraints, as basis to define a validation environment (available at http://purl.org/net/rdfval-demo) to validate RDF data according to constraints expressed by arbitrary constraint languages. Additionally, the RDF Validator can be used to validate RDF data to ensure correct syntax and intended semantics of vocabularies such as Disco, Data Cube, DCAT, and SKOS. We present how to express typical RDF constraints by multiple constraint languages and how to actually validate RDF data conforming to these constraints using the RDF Validator. The workshop participants are encouraged to use the RDF Validator during this session (only an internet browser is needed) in order to express RDF constraints they need for their individual purposes.

1. RDF Validator
purl.org/net/rdfval-demo
Thomas Bosch
GESIS – Leibniz Institute for the Social Sciences
thomas.bosch@gesis.org

2. Object Property Range
DSP, OWL 2, SPIN, SPARQL

3. Required Properties
Bibframe, DQTP, DSP, OWL 2,
ReSh, ShEx, SPIN, SPARQL

4. Default Values
on RDF Literals
SPIN, ReSh, SPARQL

5. constraint (SPIN)
owl:Thing
spin:rule [
a sp:Construct ;
sp:text """
CONSTRUCT {
?subject :keyword 'Semantic Web' ;
?subject :keyword 'Linked Data' .}
WHERE {
?subject a :SW-Publication . }
""" ; ] .

6. data
:Foundations-of-Semantic-Web-Technologies
a :Semantic-Web-Publication .
inferences
:Foundations-of-Semantic-Web-Technologies
:keyword "Semantic Web" ;
:keyword "Linked Data" .

7. constraint (ReSh)
Semantic-Web-Publication
a ResourceShape ;
property [
name "keyword" ;
propertyDefinition keyword ;
valueType xsd:string ;
defaultValue
"Semantic Web", "Linked Data" ; ] .

8. Cardinality
Restrictions
DSP, OWL 2, ShEx,
SPIN, SPARQL, ReSh

9. Negative Data Property
Constraints
ShEx, SPIN, SPARQL

10. Negative Literal
Constraints
ShEx, SPIN, SPARQL

11. Validation and
Reasoning
OWL 2

12. Transitive Object
Properties
OWL 2

13. Pattern Matching on
RDF Literals
DQTP, OWL 2 DL, ReSh, ShEx,
SPARQL, SPIN

14. Comparisons Based on
Datatype
DQTP, ShEx, SPARQL, SPIN

15. constraint
SELECT ?s WHERE {
?s %%P1%% ?v1 .
?s %%P2%% ?v2 .
FILTER ( ?v1 %%OP%% ?v2 ) }

16. test binding
dbo:deathDate < dbo:birthDate
P1 => dbo:deathDate
P2 => dbo:birthDate
OP => <

17. valid data
:AlbertEinstein
dbo:birthDate '1879-03-14'^^xsd:date ;
dbo:deathDate '1955-04-18'^^xsd:date .
invalid data
:NeilArmstrong
dbo:birthDate '2012-08-25'^^xsd:date ;
dbo:deathDate '1930-08-05'^^xsd:date .

18. RDF Literal Value
Ranges
DQTP, OWL 2 DL, SPARQL, SPIN

19. constraint
:NumberPlayersPerWorldCupTeam
a rdfs:Datatype ;
owl:equivalentClass [
a rdfs:Datatype ;
owl:onDatatype xsd:nonNegativeInteger ;
owl:withRestrictions (
[ xsd:minInclusive 1 ]
[ xsd:maxInclusive 23 ] ) ] .
:position
rdfs:range :NumberPlayersPerWorldCupTeam .

20. valid data
:MarioGoetze
:position
"19"^^:NumberPlayersPerWorldCupTeam .
invalid data
:MarioGoetze
:position
"99"^^:NumberPlayersPerWorldCupTeam .

21. Context-Specific
Disjoint Property
Groups
ShEx, SPIN, SPARQL