Project number: 224348 Project acronym: AEGIS Project title: Open Accessibility Everywhere: Groundwork, Infrastructure, Standards Starting date: 1 September 2008 Duration: 48 Months AEGIS is an Integrated Project (IP) within the ICT programme of FP7

1. Introduction Scenario Standard Conclusion
Making Heterogeneous Ontologies
Interoperable Through Standardisation
A Meta Ontology Language to be Standardised for
Ontology Integration and Interoperability (OntoIOp)
AEGIS Conference
Christoph Lange1,2 , Till Mossakowski1,3,4 ,
Christian Galinski5 , Oliver Kutz1,3
1 University of Bremen, Germany 2 Computer Science, Jacobs University Bremen, Germany
3 SFB/TR 8 “Spatial cognition”, University of Bremen, Germany 4 DFKI GmbH, Bremen, Germany
5 International Information Centre for Terminology (Infoterm), Vienna, Austria
2011-11-30
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 1

2. Introduction Scenario Standard Conclusion
Background: The OASIS EU project
OASIS = Open architecture for Accessible
Services Integration and Standardisation
Goal: an innovative reference architecture
(based on ontologies and semantic
services) that allows plug and play and
cost-effective interconnection of existing
and new services in all domains required
for the independent and autonomous
living of the elderly and enhancing their
Quality of Life
http://www.oasis-project.eu
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 2

3. Introduction Scenario Standard Conclusion
Interoperable Assistive Technology
Assistive technology increasingly relies on communication
among users,
between users and their devices, and
among these devices.
Making such ICT accessible and inclusive is costly or even
impossible
We aim at more interoperable
devices,
services accessing these devices, and
content delivered by these services
. . . at the levels of
data and metadata
data models and data modelling methods
metamodels as well as a meta ontology language
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 3

4. Introduction Scenario Standard Conclusion
Our Big Picture of Interoperability
Knowledge Infrastructure Service-Oriented Smart Environment
Architecture
Concepts/Data/Individuals Service Target (Device)
Device
rabil r
ity
fo
Ontology Service Description Target Description
inte ppings
rope
ma
Ontology Language/Logic Service Descr. Language Target Descr. Language
Data Concepts/Data/Individuals processes Service accesses Target (Device)
Device
represented in terms of satisfies conforms to
Models Ontology refers to Service Description Target Description
written in written in written in
Metamodels Ontology Language/Logic Service Descr. Language Target Descr. Language
Knowledge Software Agents Hardware
For now we focus on
the “content”/
“knowledge” column
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 4

5. Introduction Scenario Standard Conclusion
An Ambient Assisted Living (AAL) Use Case
Scenario
Clara instructs her wheelchair to get her to the kitchen (next door to
the living room). For dinner, she would like to take a pizza from the
freezer and bake it in the oven. (Her diet is vegetarian.) Afterwards
she needs to rest in bed.
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 5

6. Introduction Scenario Standard Conclusion
An Ambient Assisted Living (AAL) Use Case
Scenario
Clara instructs her wheelchair to get her to the kitchen (next door
to the living room). For dinner, she would like to take a pizza from
the freezer and bake it in the oven. (Her diet is vegetarian.)
Afterwards she needs to rest in bed.
Existing AAL ontologies (e.g. OpenAAL, http://openaal.org)
cover the core of these concepts:
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 5

7. Introduction Scenario Standard Conclusion
An Ambient Assisted Living (AAL) Use Case
Scenario
Clara instructs her wheelchair to get her to the kitchen (next door
to the living room). For dinner, she would like to take a pizza from
the freezer and bake it in the oven. (Her diet is vegetarian.)
Afterwards she needs to rest in bed.
Existing AAL ontologies (e.g. OpenAAL, http://openaal.org)
cover the core of these concepts:
. . . but not all required concepts
e.g. food ingredients ⇒ need other ontologies/modules
even need to tap into the Web of Data (product data, geodata)
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 5

8. Introduction Scenario Standard Conclusion
An Ambient Assisted Living (AAL) Use Case
Scenario
Clara instructs her wheelchair to get her to the kitchen (next door
to the living room). For dinner, she would like to take a pizza from
the freezer and bake it in the oven. (Her diet is vegetarian.)
Afterwards she needs to rest in bed.
Existing AAL ontologies (e.g. OpenAAL, http://openaal.org)
cover the core of these concepts:
. . . but not all required concepts
e.g. food ingredients ⇒ need other ontologies/modules
even need to tap into the Web of Data (product data, geodata)
. . . not necessarily at the required level of complexity
e.g. space/time ⇒ need other logics
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 5

9. Introduction Scenario Standard Conclusion
What do Devices Need to Know?
Some of the devices involved:
kitchen light switch
freezer (aware of its contents)
wheelchair (with navigation)
Different Services and Devices need to understand different
aspects of the real world at different levels of complexity.
Quote from the “Hitchhiker”
“Suddenly [the door] slid open. ‘Thank you,’
it said, ‘for making a simple door very
happy.’”
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 6

10. Introduction Scenario Standard Conclusion
Different Devices and their Knowledge
Light Switch: “light is switched on if and only if someone is in
the room and it is dark outside”
Freezer: “a vegetarian pizza is a pizza whose toppings are all
vegetarian”
Wheelchair: “two areas in a house (e.g. a working area in a
room) are either the same, or intersecting, or bordering, or
separated, or one is part of the other”
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 7

11. Introduction Scenario Standard Conclusion
Different Devices = Different Logics
Which logics can intuitively capture these notions?
Light Switch: propositional logic
“light is switched on if and only if someone is in the room and it
is dark outside” – light_on ≡ person_in_room ∧ dark_outside
Freezer: description logic (Pizza ontology)
“a vegetarian pizza is a pizza whose toppings are all vegetarian”
VegetarianPizza ≡ Pizza ∀hasTopping.Vegetarian
Wheelchair: first order logic (RCC-style spatial calculus)
“two areas in a house (e.g. a working area in a room) are either
the same, or intersecting, or bordering, or separated, or one is
part of the other”
∀a1 , a2 .equal(a1 , a2 ) ∨ overlapping(a1 , a2 ) ∨ bordering(a1 , a2 ) ∨
disconnected(a1 , a2 ) ∨ part_of(a1 , a2 ) ∨ part_of(a2 , a1 )
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 8

12. Introduction Scenario Standard Conclusion
DOL (Distributed Ontology Language)
The DOL standard (Distributed Ontology Language) specifies
a meta-language for logically heterogeneous, modular,
interlinked, and documented ontologies
with a formal semantics and an XML, RDF and text syntax
that is compatible to conforming existing and future
ontology languages.
In practice, interoperability can only be achieved via standards:
formulate consensual rules under participation of major
stakeholders (here: ontology language communities)
improve suitability of products, processes and services
facilitate communication
reduce complexity (and thus costs)
increase quality via certification
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 9

13. Introduction Scenario Standard Conclusion
The Example in DOL (Excerpt)
logic <http://purl.net/dol/logic/OWL>
ontology OurAAL = <http://openaal.org/SAM/Ontology#>
then logic <http://purl.net/dol/logic/Propositional> : {
props light_on, person_in_room, dark_outside
. light_on <=> person_in_room / dark_outside
with person_in_room |-> Room that inverse locatedIn Person min 1
%% also establish links to OpenAAL’s Device
} then logic <http://purl.net/dol/logic/OWL> : {
Class: VegetarianPizza
EquivalentTo: Pizza that hasTopping only Vegetarian
Individual: <http://productdb.org/ean/4001724819806>
Facts: hasTopping Tomato, hasTopping Mozzarella %% and nothing else
%% also connect Pizza to the OpenAAL Devices Freezer and Oven
} then logic <http://purl.net/dol/logic/CommonLogic> : {
. (forall (a1 a2) (or (equal a1 a2) ... (part_of a2 a1))
%% plus another axiom that makes the "or" exclusive
with %% establish link to OpenAAL’s Room connectedTo Room
} end
Relevant DOL features used here: literal inclusion of existing
languages; modular reuse; links between ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 10

14. Introduction Scenario Standard Conclusion
The Example in DOL (Excerpt)
logic <http://purl.net/dol/logic/OWL>
ontology OurAAL = <http://openaal.org/SAM/Ontology#>
then logic <http://purl.net/dol/logic/Propositional> : {
props light_on, person_in_room, dark_outside
. light_on <=> person_in_room / dark_outside
with person_in_room |-> Room that inverse locatedIn Person min 1
%% also establish links to OpenAAL’s Device
} then logic <http://purl.net/dol/logic/OWL> : {
Class: VegetarianPizza
EquivalentTo: Pizza that hasTopping only Vegetarian
Individual: <http://productdb.org/ean/4001724819806>
Facts: hasTopping Tomato, hasTopping Mozzarella %% and nothing else
%% also connect Pizza to the OpenAAL Devices Freezer and Oven
} then logic <http://purl.net/dol/logic/CommonLogic> : {
. (forall (a1 a2) (or (equal a1 a2) ... (part_of a2 a1))
%% plus another axiom that makes the "or" exclusive
with %% establish link to OpenAAL’s Room connectedTo Room
} end
Relevant DOL features used here: literal inclusion of existing
languages; modular reuse; links between ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 10

15. Introduction Scenario Standard Conclusion
The Example in DOL (Excerpt)
logic <http://purl.net/dol/logic/OWL>
ontology OurAAL = <http://openaal.org/SAM/Ontology#>
then logic <http://purl.net/dol/logic/Propositional> : {
props light_on, person_in_room, dark_outside
. light_on <=> person_in_room / dark_outside
with person_in_room |-> Room that inverse locatedIn Person min 1
%% also establish links to OpenAAL’s Device
} then logic <http://purl.net/dol/logic/OWL> : {
Class: VegetarianPizza
EquivalentTo: Pizza that hasTopping only Vegetarian
Individual: <http://productdb.org/ean/4001724819806>
Facts: hasTopping Tomato, hasTopping Mozzarella %% and nothing else
%% also connect Pizza to the OpenAAL Devices Freezer and Oven
} then logic <http://purl.net/dol/logic/CommonLogic> : {
. (forall (a1 a2) (or (equal a1 a2) ... (part_of a2 a1))
%% plus another axiom that makes the "or" exclusive
with %% establish link to OpenAAL’s Room connectedTo Room
} end
Relevant DOL features used here: literal inclusion of existing
languages; modular reuse; links between ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 10

16. Introduction Scenario Standard Conclusion
The Example in DOL (Excerpt)
logic <http://purl.net/dol/logic/OWL>
ontology OurAAL = <http://openaal.org/SAM/Ontology#>
then logic <http://purl.net/dol/logic/Propositional> : {
props light_on, person_in_room, dark_outside
. light_on <=> person_in_room / dark_outside
with person_in_room |-> Room that inverse locatedIn Person min 1
%% also establish links to OpenAAL’s Device
} then logic <http://purl.net/dol/logic/OWL> : {
Class: VegetarianPizza
EquivalentTo: Pizza that hasTopping only Vegetarian
Individual: <http://productdb.org/ean/4001724819806>
Facts: hasTopping Tomato, hasTopping Mozzarella %% and nothing else
%% also connect Pizza to the OpenAAL Devices Freezer and Oven
} then logic <http://purl.net/dol/logic/CommonLogic> : {
. (forall (a1 a2) (or (equal a1 a2) ... (part_of a2 a1))
%% plus another axiom that makes the "or" exclusive
with %% establish link to OpenAAL’s Room connectedTo Room
} end
Relevant DOL features used here: literal inclusion of existing
languages; modular reuse; links between ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 10

17. Introduction Scenario Standard Conclusion
The Example in DOL (Excerpt)
logic <http://purl.net/dol/logic/OWL>
ontology OurAAL = <http://openaal.org/SAM/Ontology#>
then logic <http://purl.net/dol/logic/Propositional> : {
props light_on, person_in_room, dark_outside
. light_on <=> person_in_room / dark_outside
with person_in_room |-> Room that inverse locatedIn Person min 1
%% also establish links to OpenAAL’s Device
} then logic <http://purl.net/dol/logic/OWL> : {
Class: VegetarianPizza
EquivalentTo: Pizza that hasTopping only Vegetarian
Individual: <http://productdb.org/ean/4001724819806>
Facts: hasTopping Tomato, hasTopping Mozzarella %% and nothing else
%% also connect Pizza to the OpenAAL Devices Freezer and Oven
} then logic <http://purl.net/dol/logic/CommonLogic> : {
. (forall (a1 a2) (or (equal a1 a2) ... (part_of a2 a1))
%% plus another axiom that makes the "or" exclusive
with %% establish link to OpenAAL’s Room connectedTo Room
} end
Relevant DOL features used here: literal inclusion of existing
languages; modular reuse; links between ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 10

18. Introduction Scenario Standard Conclusion
The Example in DOL (Excerpt)
logic <http://purl.net/dol/logic/OWL>
ontology OurAAL = <http://openaal.org/SAM/Ontology#>
then logic <http://purl.net/dol/logic/Propositional> : {
props light_on, person_in_room, dark_outside
. light_on <=> person_in_room / dark_outside
with person_in_room |-> Room that inverse locatedIn Person min 1
%% also establish links to OpenAAL’s Device
} then logic <http://purl.net/dol/logic/OWL> : {
Class: VegetarianPizza
EquivalentTo: Pizza that hasTopping only Vegetarian
Individual: <http://productdb.org/ean/4001724819806>
Facts: hasTopping Tomato, hasTopping Mozzarella %% and nothing else
%% also connect Pizza to the OpenAAL Devices Freezer and Oven
} then logic <http://purl.net/dol/logic/CommonLogic> : {
. (forall (a1 a2) (or (equal a1 a2) ... (part_of a2 a1))
%% plus another axiom that makes the "or" exclusive
with %% establish link to OpenAAL’s Room connectedTo Room
} end
Relevant DOL features used here: literal inclusion of existing
languages; modular reuse; links between ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 10

19. Introduction Scenario Standard Conclusion
ISO Standardization Roadmap
The standardization of DOL (ISO 17347) so far involves experts
from ≈ 15 countries and various ontology-related communities.
Now: Working Drafts, towards Committee Draft (each stage
reviewed by experts, voted upon)
2013: Draft International Standard
2015: Final Draft, then International Standard
http://ontolog.cim3.net/cgi-bin/wiki.pl?OntoIOp
DOL – a meta-language for logically heterogeneous,
modular, interlinked, and documented ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 11

20. Introduction Scenario Standard Conclusion
One Logic for the Ontology?
Why not everything in first order logic?
The more expressive a logic, the less computationally favorable!
Specialized tools for specific logics exist:
provers, model finders, consistency checkers, query engines
Ontologies in different logics exist as a matter of fact
e.g. DOLCE (first order logic): general notions of space, time,
parthood
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 12

21. Introduction Scenario Standard Conclusion
Requirements
DOL should be generally applicable, open, and extensible
DOL shall be a logic-agnostic metalanguage
DOL should have user- and machine-readable serializations
DOL should have a well-defined formal, logic-based
semantics
DOL should allow for expressing logically heterogeneous
ontologies (and literal reuse of existing modules)
DOL should allow for expressing links between ontologies
DOL should allow for writing down ontologies and ontology
links as implicitly as possible and as explicitly as needed
DOL should allow for rich annotation and documentation of
ontologies
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 13

22. Introduction Scenario Standard Conclusion
The Onto-Logical Translation Graph
OBOOWL
OBO 1.4
bRDF
EL QL RL RDF
PL
OWL RDFS
DDLOWL
RDFSOWL grey: no fixed expressivity
green: decidable ontology languages
yellow: semi-decidable
ECoOWL
FOL=
orange: some second-order constructs
red: full second-order logic
CL ECoFOL Rel-S
F-logic
subinstitution
CASL theoroidal subinstitution
simultaneously exact and
FOLms= model-expansive comorphisms
HOL
model-expansive comorphisms
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 14

23. Introduction Scenario Standard Conclusion
Conformance Criteria
DOL should work with any existing or future ontology
language (if the latter conforms!)
We shall establish the conformance of OWL, Common Logic,
RDFS, F-logic, UML class diagrams, and OBO
Conformance of a logic (directly or by translation):
semantic conformance > entailment conformance
Conformance of a serialization:
XML conformance > RDF conformance > text conformance >
standoff markup conformance
Conformance of a document
(“Is this document a DOL ontology?”)
Conformance of an application:
A DOL-conforming application produces DOL-conforming
documents!
Lange et al. (U. Bremen/Infoterm) Making Heterogeneous Ontologies Interoperable Through Standardisation 2011-11-30 15