11th International Conference on Semantic Systems (SEMANTiCS 2015)

1. The Role of Reasoning for
RDF Validation
Thomas Bosch, Gesis - Leibniz Institute for the Social Sciences
Erman Acar, University of Mannheim
Andreas Nolle, Albstadt-Sigmaringen University
Kai Eckert, Stuttgart Media University

2. RDF Validation
• high data quality
• XML validation
• RDF Validation Workshop
• working groups
– W3C Data Shapes Working Group
– DCMI RDF Application Profiles Task Group
• existing constaint languages
(ShEx, OWL 2, DSP, ReSh, SPIN, SPARQL, …)

3. Constraint Types
http://purl.org/net/rdf-validation
• database of 81 requirements on RDF validation
• based on findings of WGs and case studies
• from case studies to solutions and back
• requirements correspond to constraint types

4. RDF Validator
http://purl.org/net/rdfval-demo
example: disjoint classes

5. what is the role reasoning plays
for RDF Validation?
why is reasoning beneficial for validation?
how to overcome the major shortcomings
when validating?

6. (1) reasoning may resolve violations
Book ⊑  author.Person
Book(Huckleberry-Finn)
author(Huckleberry-Finn, Mark-Twain)
→ Person(Mark-Twain)

7. (2) reasoning may cause violations
Book ⊑ Publication
Publication ⊑
∃ publisher.Publisher
Book(Huckleberry-Finn)

8. (3) reasoning solves redundency
Publication ⊑
∃ publicationDate.xsd:date
Book ⊑ Publication
Conference-Proceeding ⊑ Publication
Journal-Article ⊑ Publication

9. for which constraint types
reasoning may be performed
prior to validation
to enhance data quality?

10. constraint types
with and without reasoning
• 𝑹: set of constraint types with reasoning
– 43.2%
– RQL: OWL 2 QL reasoning
– RDL: OWL 2 DL reasoning
– determine if reasoning should be performed on
different levels
• 𝑹: set of constraint types without reasoning
– 56.8%

11. constraint types with reasoning
sub-properties
editor ⊑ creator
editor (A+Journal-Volume, A+Editor)
creator (A+Journal-Volume, A+Editor)

12. constraint types with reasoning
property domain
∃ author.⊤ ⊑ Publication
author(Alices-Adventures-In-Wonderland,
Lewis-Carroll)
rdf:type(Alices-Adventures-In-Wonderland,
Publication)

13. constraint types without reasoning
literal pattern matching
ISBN a rdfs:Datatype ;
owl:equivalentClass [ a rdfs:Datatype ;
owl:onDatatype xsd:string ;
owl:withRestrictions
([ xsd:pattern "^d{9}[d|X]$" ])] .
Book ⊑  identifier.ISBN

14. constraint types without reasoning
allowed values
Book ≡  subject.
{Computer-Science, Librarianship}

15. How efficient
in terms of runtime
validation is performed
with and without reasoning?

16. performance in worst case
• computational complexity
• mapping to description logics

17. performance in worst case
validation type complexity class
𝑹 PSPACE-Complete
RQL PTIME
RDL N2EXPTIME
PTIME ⊆ PSPACE-Complete ⊆ N2EXPTIME

18. for which constraint types
validation results differ
(1) if the CWA or the OWA and
(2) if the UNA or the nUNA is
assumed?

19. • reasoning and validation assume different semantics
– reasoning: OWA + nUNA
– validation: CWA + UNA
• different semantics lead to different validation results
• does the constraint type depend on the CWA?
• does the constraint type depend on the UNA?
semantics

20. CWA dependent constraint types
minimum qualified cardinality restrictions
Publication ⊑ ≥1 author.Person

21. CWA independent constraint types
disjoint classes
Book ⊓ JournalArticle ⊑ ⊥

22. UNA dependent constraint types
functional properties
funct(title)
title(The-Adventures-of-Huckleberry-Finn,
"The Adventures of Huckleberry Finn")
title(The-Adventures-of-Huckleberry-Finn,
"Die Abenteuer des Huckleberry Finn")

23. UNA independent constraint types
literal value comparison
birthDate(Albert-Einstein, "1955-04-18")
deathDate(Albert-Einstein, "1879-03-14")
birthDate(Albert_Einstein, "1879-03-14")
deathDate(Albert_Einstein, "1955-04-18")
owl:sameAs(Albert-Einstein, Albert_Einstein)

24. • CWA dependent: 56.8%
• UNA dependent: 66.6%
evaluation results on semantics

25. Contributions
1. role reasoning plays for validation
2. how reasoning improves data quality
3. efficiency with and without reasoning
4. dependency on different semantics