MontoloStats
Ontology Modeling Statistics
Sven Lieber, Ben De Meester, Anastasia Dimou and Ruben Verborgh
K-Cap 2019, Marina Del Rey United States
Sven Lieber - w3id.org/montolo

K-CAP 2001
1st Knowledge Capture Conference
Oct 22-23, 2001
Victoria, B.C., Canada
“Driven by today's internet culture and knowledge-based
industries, the study of knowledge acquisition has a renewed
value.”
18 years later: How do we model acquired knowledge nowadays?
RDF1.1, OWL, Linked Data, shapes, Ontology Engineering
Sven Lieber - w3id.org/montolo

Different use cases demand differently modeled ontologies
3
Use case
Email
Person
1
Birthday
2
Regular ExpressionCompany
Existing ontologies
...
...
≠
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Take home message
4
Whatever is modeled has impact on reuse,
do not forget to take different use cases into account
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Ontology Reuse and metadata
Restriction type statistics
Analysis of LOV and BioPortal statistics
Lessons learned and future work/limitations
5 Sven Lieber - w3id.org/montolo

Discover and assess ontologies based on restriction use
6
Possible ontology reuse candidates
(colors = different restriction
types)
Restriction type
use statistics Use case
Sven Lieber - w3id.org/montolo

Ontology Reuse and metadata
Restriction type statistics
Analysis of LOV and BioPortal statistics
Lessons learned and future work/limitations
7 Sven Lieber - w3id.org/montolo

Restrictions: types and expressions in Montolo
8
Email
Person
1
Birthday
2
Regular ExpressionCompany
≠
Restriction types
For example disjointness
Exact cardinality
Literal pattern
≠
2
Regular Expression
Restriction type expressions
Different terms within or across
vocabularies, e.g.:
owl:disjointWith and
owl:AllDisjointClasses
Sven Lieber - w3id.org/montolo

Computing the statistics - overview
9
LODStats
Montolo
Stats
Modules to
detect
restriction types
Extendible number of
ontology repositories
Modular creation of
restriction use statistics
DataCube and PROV
annotated statistics
LOV
Bio
Portal
660
ontologies
565
ontologies
31,850
observations
18 restriction types
Sven Lieber - w3id.org/montolo

Ontology Reuse and metadata
Restriction type statistics
Analysis of LOV and BioPortal statistics
Lessons learned and future work/limitations
10 Sven Lieber - w3id.org/montolo

How many ontologies use each restriction type?
11
A few often used
restriction types and a
long tail both
in LOV and BioPortal
Restriction types
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Negligible number of literal value restrictions
12
Almost no literalRanges
restrictions
literalPattern not used
at all
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Property and cardinality restrictions in the tail
13
Tail mostly consists of
property-based and
cardinality-based
restrictions expressed
using OWL terms
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LOV vs BioPortal: qualified cardinalities
14
Qualified cardinalities
preferred in BioPortal
ontologies
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LOV vs BioPortal: unqualified cardinalities
15
Unqualified cardinalities
preferred in LOV
ontologies
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Certain restrictions slightly more used in BioPortal
16
BioPortal ontologies
use certain restrictions
more often
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Domain and range used less in BioPortal
17
More domain/range
Restrictions in LOV
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Total numbers indicate more BioPortal concepts
18
Several restriction types
used considerably more
often
Compared to LOV: more
concepts in BioPortal
and/or
some ontologies disturb
the results
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Disjoint properties and disjoint classes
19
:Person
owl:disjointWith :Car ;
owl:disjointWith :Boat ;
owl:disjointWith :Company .
More concepts/properties
declared disjoint
using list-based expression
_b1: a owl:AllDisjointWith ;
owl:members
(:Person :Company
:Car :Plane) .
Single property-based
List-based
Single property-based expression
used in more ontologies
Sven Lieber - w3id.org/montolo

Exact cardinality expressions
20
:hasWheels
owl:minCardinality 4 ;
owl:maxCardinality 4 .
Ontologies mostly use this
expression
:hasWheels
owl:cardinality 4 .
Equal min/max
Property-based
Barely used
3 times in 2 LOV ontologies
Not used in BioPortal ontologies
Sven Lieber - w3id.org/montolo

Ontology Reuse and metadata
Restriction type statistics
Analysis of LOV and BioPortal statistics
Lessons learned and future work/limitations
21 Sven Lieber - w3id.org/montolo

Lessons learned: restriction modeling
More concrete Ontology Engineering guidelines
Implicit restriction use patterns found,
but explicit guidelines needed for
practical needs in a changing environment
22 Sven Lieber - w3id.org/montolo

Lessons learned: restriction modeling
Investigation in modeling tools required
Is the creation of all restriction types supported by
modeling tools? Are these tool appealing to do so?
23 Sven Lieber - w3id.org/montolo

Raised questions: impact of restriction types
Correlation between restriction type use
and ontology reuse?
24
How are different restriction types
involved in Knowledge Graph quality issues?
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Future work
Evaluate to which extent MontoloStats improves
the process of ontology reuse.
25
Investigate novel Ontology Engineering activities
with respect to the modeling of restrictions.
Sven Lieber - w3id.org/montolo

Limitations
Currently not all possible restriction types
and expressions considered
26
Incorporate imported restrictions and statistics
regarding number of classes/relationships
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Take home message
27
Whatever is modeled has impact on reuse,
do not forget to take different use cases into account
Check restrictions stats at by appending
your favorite ontology prefix
https://w3id.org/montolo/data/montolo-stats/latest/voc/ + prefix
Sven Lieber - w3id.org/montolo

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!
Sven Lieber - w3id.org/montolo

LODStats
Comprehensive and extendible statistics
29
Detector
owl:disjointWith
Detector
owl:AllDisjointClasses
:Person
owl:disjointWith :Vehicle ;
owl:disjointWith :Company .
_b1: a owl:AllDisjointWith ;
owl:members
(:Car :Boat
:Plane :Bike) .
Restriction type module:
disjoint classes
Computed measures following DataCube
Occurrence
measure
i++
Occurrence
measure
(n2-n) / 2
[] a qb:Observation ;
mon:restrictionTypeDimension
mon:disjointClasses ;
mon:detectorVersionDimension
mon:owlDisjointWith ;
mon:restrictionTypeOccurrence 2 ;
Ontology with restrictions
..
..
[] a qb:Observation ;
mon:restrictionTypeDimension
mon:disjointClasses ;
mon:detectorVersionDimension
mon:owlAllDisjointClasses ;
mon:restrictionTypeOccurrence 6 ;
Sven Lieber - w3id.org/montolo