=Paper=
{{Paper
|id=Vol-516/paper-23
|storemode=property
|title=The newsEvents Ontology - An Ontology for Describing Business Events
|pdfUrl=https://ceur-ws.org/Vol-516/pap13.pdf
|volume=Vol-516
|dblpUrl=https://dblp.org/rec/conf/semweb/LoschN09
}}
==The newsEvents Ontology - An Ontology for Describing Business Events==
https://ceur-ws.org/Vol-516/pap13.pdf
The newsEvents Ontology
An Ontology for Describing Business Events
Uta Lösch and Nadejda Nikitina
AIFB, Universität Karlsruhe, Germany
{uhe,nani}@aifb.uni-karlsruhe.de
Abstract. In the broader context of the development of an ontology-
based new event detection system, we are developing the newsEvents
ontology which allows modeling business events, the affected entities and
relations between them. This paper presents requirements for and a first
version of this ontology. A pattern-based approach to the design of the
ontology was taken. Thereby a new useful pattern - the EventRole pat-
tern - was identified and specified.
1 Introduction
The analysis of news and the estimation of their market impact is an important
issue for traders in financial markets. As the amount of news that is made avail-
able is huge, at least a partial automation of the analysis process is desirable.
The goal is to filter relevant news, to provide an aggreggated view on their con-
tent and to thus enable the users to only read those news that are really relevant
for them. The relevance of a piece of news depends on their relevance for the
traders’ interests (i.e. is it about an entity that the trader is interested in) and
its novelty. These two aspects are rather independent of each other and can thus
be approached separately.
The idea of our work is to study which benefits ontologies may offer for
the two described aspects. In order to study this problem, an ontology is needed
which allows to describe relevant entities and events in the business news context.
To the best of our knowledge no such ontology exists. We therefore decided to
build one for the use in the kind of system we have described above. In this
paper, the newsEvents ontology, which was developed for that purpose, will be
presented.
In the task of relating news to a user’s interest ontology-based annotations
may provide a condensed representation of a text’s content. A query on these
annotations can be used to describe the user’s information need. A similar system
has been described by [4].
This work has been supported by the Deutsche Forschungsgemeinschaft in the scope
of the graduate school of Information Management and Market Engineering and
by the EU through in the IST project NeOn (IST-2006-027595, http://www.neon-
project.org/.
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For the task of discovering new events, to which we refer as the new event
detection problem, the annotation of texts with ontology entities allows for as-
sessing their content and relating news to each other based on these annotations.
The introduction of additional features that are based on annotations in the clus-
tering task seems promising as it allows a more specific analysis of the content
and as it enables a better distinction between similar events.
More precisely, annotations will be obtained from a state-of-the-art tool
(OpenCalais1 has been chosen for this task). To include the annotations in the
clustering task a similarity measure that takes into account the similarity be-
tween annotations will be introduced. However, the provided annotations do not
offer much structure, only a list of annotation types and some properties for
each type are defined. A taxonomy on the annotation types is not defined. The
newsEvents ontology will allow for the description of the current state of the
domain and of events as reported in news. The ontology provides a formalisa-
tion of this kind of information that includes more background knowledge than
OpenCalais’ annotations.
The rest of the paper is structured as follows: Section 2 describes related
work, section 3 describes our requirements for the ontology, section 4 describes
the ontology we built, section 5 describes the newly defined EventRole pattern,
before we conclude in section 6.
2 Related Work
While to the best of our knowledge no ontology exists which aims at describing
companies, their relations among each other and the most important events,
there is a number of models which address part of the scope of the intended
ontology.
OpenCalais has defined a schema which is used for the annotation of news
texts, in which events and entities are annotated. While the scope is quite similar
to the scope of the newsEvents ontology, it only defines a list of annotation types
and, for the complex annotations, the slots that have to be filled. The goal when
defining the newsEvents ontology was to provide a model of the domain that
provides more background knowledge on event and entity types and that is able
to relate different annotations to each other.
The classification of news according to their content is very important for
news providers. Therefore, various annotation languages have been defined for
this purpose: while IIM2 is today only used for annotating photos, its successors
NITF3 and NewsML4 are still in use. However, their primary concern is to have
a standardized format for providing and exchanging news.
1
http://www.opencalais.com
2
The Information Interchange Model, http://www.iptc.org/IIM/
3
The News Industry Text Format, http://www.nitf.org
4
The News Meta Language, http://www.newsml.org
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The most important entity types (and also some events) are also defined in
top-level ontologies such as Cyc5 or Proton6 . However, these ontologies are not
detailed enough for our use case.
There is a number of ontologies in the finance domain. The LSDIS Finance
ontology7 and the dip Ontology [1] both describe actors and products in the stock
markets. However, these ontologies do not include any description of events.
3 Competency questions
As described above, the newsEvents8 ontology shall be used for describing events
which are relevant in a business context and for assessing similarity between
different events. It will also be used for modeling the current information that
is available about the economy and for determining whether a user might be
interested in a new event that is reported. In the future, it may also be considered
whether there are recurring patterns of series of events where the next events
may be anticipated. It may also be useful for studying the impact of events on
financial markets.
As the latter use cases may only be interesting in the future and are not the
main motivation for developing the ontology, no special attention has been paid
to them when developing the first version of the ontology. It will however be
extended accordingly in the future.
When developing the ontology, the goal was to have as little modeling efforts
as possible. Therefore, a pattern-based approach to its design was taken.
The first step in the development of the ontology was the definition of a set
of competency questions. Competency questions are questions that the ontology
should be able to answer. Ideally, the ontology should be able to answer all and
only the competency questions - no superfluous additional information should be
included in the model. For a more detailed discussion of competency questions
see [3]. The following questions were defined:
– Related to the history of an event
• Is there any information on a specific event already available? This ques-
tion serves to determine whether a specific event has already been re-
ported on. If this is not the case, the event is definitely new - information
about it has to be integrated into the knowledge base. Additionally, its
novelty will be high.
• In which order and in which timeframe was information on a specific
event published? The purpose of this question is to determine the devel-
opment of the information that is made available on an event. This will
help to study the development of the history of a single event. It may
5
The Cyc knowledge base, http://www.cyc.com
6
The proton ontology, http://proton.semanticweb.org
7
http://lsdis.cs.uga.edu/projects/meteor-s/wsdl-s/ontologies/LSDIS FInance.owl
8
The ontology is available at
http://www.aifb.uni-karlsruhe.de/WBS/uhe/ontologies/newsEvents.owl
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however also help to determine patterns of how event histories look like
and thus to anticipate new information.
– Related to the assessment of similarity
• How similar are two entities? The similarity of two entities may be de-
fined through their properties, like entity type, name, position, location,
industry, etc. The assessment of entity similarity is needed for the as-
sessment of event similarity, but it will also help to identify entities on
which similar events may have similar impact, entities which may have
a similar history, or entities that may be interesting for a user based on
the interests he has stated explicitely.
• How similar are two events? The similarity of two events is needed for
deciding whether two events are in fact the same. Furthermore, if two
events are very similar, they may be interesting for the same users and
the history of one event may allow for anticipating future developments
concerning the other event.
– Related to relations between entities
– Which products does a company produce? Which industry does a company
belong to? Where is a company located? Although these questions may seem
very heterogenuous at first sight, they all serve for finding entities and events
that are related to a user’s interests. For example, if he is interested in cars,
he may be interested in all news that relate to car manufacturing companies.
4 The newsEvents ontology
Based on the requirements presented in the previous section, we have developed
a first version of the newsEvents ontology. It describes various entity types that
are relevant in business news as well as important events, in which described
entities may be involved.
For the development of the ontology we tried to follow a pattern-based ap-
proach. Especially, we found the use of content design patterns helpful. These
are small ontologies - typically consisting of two to ten classes and relations
among them, which describe typical modeling problems arising in different do-
mains. These patterns were proposed by Gangemi and Presutti [2] [6]. The goal
is facilitate the design of the ontology by providing building blocks which can be
composed, specialized or instantiated and thus be adapted to a specific domain.
As OpenCalais is used for obtaining annotations, the annotation types Open-
Calais defines were taken as a starting point for the definition of the concepts
that should be represented in the ontology.
After the most important concept types were chosen, the next step consisted
in identifying the patterns that could be reused for defining the newsEvents
ontology. Using the patterns described below, the description of most of the
event and entity types turned out to be rather straight forward. As the whole
ontology is quite big and complex, we only show parts of it to illustrate the use
of design patterns:
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– TimeIndexedParticipation. This pattern describes the involvement of ob-
jects in an event at a certain point in time. This pattern can be reused
for the description of events like Acquisition, Merger, IPO, etc. The vari-
ous event types could be described as specialisations of the concept Event,
its participants could be defined through the use of specialisations of the
hasParticipant property and of the Participant class, which are defined
in the Participation pattern. The association of an event with the time at
which it is happening is possible through the TimeIndexedParticipation
concept, which relates events and their participants to a time component.
– Situation. This very general pattern can be used for the description of com-
plex relations, like CompanyTicker. The latter describes a company which
is traded at a specific stock exchange and has a specific ticker symbol there.
This could be modeled by defining the concept CompanyTicker as subcon-
cept of Situation.
– Place. This pattern defines how places and locations should be described in
an ontology. The newsEvents ontology describes various concepts, especially
event types, that happen at a certain location. The place pattern allows to
model these locations and relations among them.
– ObjectRole. This pattern allows to describe the different roles an entity of
a specific type may play. This pattern is useful for defining the different
roles an entity may play in an event or in a relation among entities. For
example, an Acquisition describes the event of one company acquiring
another one. Obviously, there are two entities of the same type, i.e. two
companies involved. One company is the acquiring company, the other one
the acquired company - the companies thus play different roles in the event.
To address the problem of roles in events we have defined the EventRole
pattern, which will be described in section 5.
A taxonomy of event and entity types has been defined, which is needed to
allow for the calculation of similarities between different event types.
To distinguish between the different type of events, we introduced additional
classes for describing events that have a similar meaning. For this purpose classes
like CompanyCollaboration, LegalIssue, or StockEvent were introduced. None
of these classes defines concrete events. It is merely used as a grouping element.
For example, the class CompanyCollaboration has the subclasses Alliance,
BusinessRelation, JointVenture, and Merger. Each of these events describes
a way in which two companies may choose to collaborate.
Entities were also grouped in a hierarchy. Here, grouping was chosen accord-
ing to which roles an entity may play in events. Most importantly, we created
a class LegalEntity which describes both legal and natural persons, i.e. every
entity that may be an actor in an event.
5 The EventRole pattern
When building the ontology, design patterns could be used to address most of the
modeling problems that were encountered. However, no obvious solution seemed
191
to be available for the case where two entities of the same type are involved
in the same event. This is however a recurring situation. Examples in our use
case are acquired and acquiring company, provider and customer, plaintiff and
suedEntity, etc. The occurrence of this kind of situation is not restricted to the
business domain: an obvious example in an everyday context is a visit, where
there is a visitor and a person that is visited.
The problem can be solved by composing the patterns Participation and
ObjectRole. The idea is that the participants in an event are not described by
their entity type, but by the role they are taking in the event. The resulting
pattern is depicted in figure 1.
A new class EventRole has been introduced which serves as connector be-
tween the two original patterns. The EventRole class is used to describe the role
that an entity plays in an event. Therefore, it is a specialization of the Role and
the Object class. For each role an entity can play in an event, this class should
be specialized. Additionally, the property hasParticipant should be specialized
for each of the entity’s roles and the thus defined properties should be declared
disjoint. Thus, each object can only have one role in a given event.
To show how the pattern can be adapted to a specific use case, consider the
definition of an acquisition event. An acquisition is the event of one company, the
acquiring company, buying another one, the acquired company. Two companies
are involved in this event, but it makes a huge difference for company A if it is
acquired by company B or whether it acquires company B. Therefore, the event
roles AcquiringCompany and AcquiredCompany have been defined. They both
are roles of Company. The class Acquisition is then defined as a subclass of
Event. Additionally, we defined the restriction that each acquisition has at least
one acquiring company and at least one acquired company, but at most 2 par-
ticipants. The properties hasAcquiringCompany and hasAcquiredCompany were
specified as subproperties of the hasParticipant property. The two properties
are defined as being disjoint.
6 Conclusion
The paper presented an ontology which can be used to describe events and
entities in a business news context. Patterns have proven to be very useful for
the design of the ontology as they directly solve many of the modeling issues
that were encountered in the engineering process.
One of the recurring problems encountered while modeling the ontology was
the description of the roles entities take in an event. The EventRole pattern has
been proposed in order to solve this issue.
In the future, the proposed ontology will be refined and extended such that
relations between events (especially causal relationships) may be included in the
ontology.
Additionally, procedural knowledge (following our proposal in [5]) will be
associated with the ontology, such that automatic updates of an entity’s state
after being affected by an event become possible. The ontology, which can then
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Fig. 1. The role event pattern and its adaptation for modeling acquisitions
automatically adapt to changes in the domain, will then be ready to be used in
the new event detection process.
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