1.
Policy-compliant data
processing: RDF-based
restrictions for data-protection
Sven Lieber, supervised by Anastasia Dimou and Ruben Verborgh
ISWC 2019, Doctoral Consortium in Auckland

2.
2
Policy (App specific)
Religion
Email
Person
Sensitive
1
hasEmail maxCount
Birthday
Personal
Violation if personal data used
without informed consent
Closed world constraints on data
“Simple” modeling example: Person
Consent
1
hasEmail maxCount 3

3.
3
Ontologies are carefully designed and a lot of design
decisions need to be made

4.
Ontologies are the result of a carefully executed process
4
Ontology or
any knowledge
representation in RDF
Ontology Engineering process
Existing
ontologies
Needs and
Requirement
s
Concepts,
Relationships,
Restrictions

5.
Currently unclear how needs and requirements are
addressed by expressed restrictions
5
Ontology
Ontology Engineering processNeeds and
Requirement
s
Constraints

6.
Unknown how restrictions are used in existing ontologies
6
OntologyOntology Engineering process
Existing
ontologies
Needs and
Requirement
s
Concepts,
Relationships,
Restrictions

7.
Relevancy
7
Different use cases and level of formality
Ontology with less and with more restrictions
Annotation
e.g. schema.org
Reasoning
e.g. pizza ontology

8.
My research is relevant regarding the modeling of
constraints when developing ontologies
8
Ontology with axioms
RDFS, OWL
Constraints on ontology concepts’
Instance data
SHACL, ShEx

9.
Restriction modeling in RDF as axioms, constraints or as
part of policies is relevant to compliance checking
9
Privacy-aware data processing
Compliance assessments to address this recognized need

10.
Approach overview
10
Ontology
Ontology Engineering process
Existing
ontologies
Needs and
Requirement
s
Constraints
Concepts,
Relationships,
Restrictions
1) Inform
2) Compare existing activities
and propose new activities
3) Apply on privacy use case

11.
Related work: Restrictions can be modeled in a lot of
different ways, but currently no guidelines when to use what
11
Existing
ontologies
Concepts,
Relationships,
Restrictions
Closed world constraints (SHACL, ShEx)
Open world axioms (OWL, RDFS)
Restriction types in data quality

12.
12
Existing
ontologies
Concepts,
Relationships,
Restrictions
How can we measure ontologies’ restriction use in
a complete way?
We can measure restriction use by obtaining
statistics regarding restriction types and
their different expressions.
Research to understand the use of restrictions in RDF-
based vocabularies

13.
13
Existing
ontologies
Concepts,
Relationships,
Restrictions
Create statistics about the use of restriction types
and expressions of ontologies from common
ontology repositories
Verify completeness of restriction type statistics
by comparison with ground truth
We want to create a statistical dataset about
restriction use and evaluate its completeness

14.
Preliminary Results indicate different use of
Restrictions and implicit modeling patterns
14
Existing
ontologies
Concepts,
Relationships,
Restrictions
Restriction use analysis of LOV and BioPortal
MontoloStats -
Ontology Modeling Statistics
https://w3id.org/montolo
Different restriction types

15.
Second part of PhD covers the engineering process
15
OntologyOntology Engineering process
Existing
ontologies
Needs and
Requirement
s
Concepts,
Relationships,
Restrictions
✓

16.
16
Ontology Engineering processNeeds and
Requirement
s
Related work: Ontology Engineering methodologies and
Ontology Design patterns, but unclear how restriction
modeling is supported
Ontology
Constraints

17.
17
How can we support users in restriction modeling
involving axioms and constraints?
We can define a restriction modeling activity which provides
more support to model restrictions compared to existing activities.
Extend existing ontology engineering
activities to support restriction modeling
Ontology Constraints

18.
18
How applicable is our restriction modeling
activity in a privacy use case?
Automatic privacy compliance checks by supporting the
knowledge engineer in the creation of concepts, axioms,
constraints and policies.
Apply restriction modeling activity in privacy use case to
support users in compliance assessments

19.
Our approach to addressing the research
19
Define an Ontology Engineering activity to model
restrictions based on existing best practices
Apply activity in a different use cases
Ontology
Ontology Engineering processNeeds and
Requirement
s
Constraints

20.
User evaluations and case studies to evaluate our approach
20
Constraints
User evaluations comparing restriction modeling
activity with state-of-the-art activities
Perform a case study
in the privacy domain
Ontology
Ontology Engineering processNeeds and
Requirement
s

21.
Preliminary Results cover proof-of-concepts
regarding privacy-related annotations and
a review of ontology engineering literature
21
Ontology Engineering processNeeds and
Requirement
s
Ontology

22.
Complement open world axioms with closed world
constraints when systematically building knowledge
Compliance assessments of privacy-aware data
processing currently either axioms or constraints

23.
Sven Lieber
PhD researcher semantic intelligence
E Sven.Lieber@ugent.be
T +32 9 331 49 59
https://sven-lieber.org
@SvenLieber
Interested in
- Ontology Engineering?
- Shapes?
- Privacy?
Come and talk to me!