Database Reference
In-Depth Information
buildings recorded within Merea Maps' Linked Data and classify a subset of them
as of historic interest, using the Uniform Resource Identifiers (URIs) provided by
Merea Maps as the hook on which to link heritage-related data about those buildings.
So, Merea Maps wants to provide a general topographic model of the Island of Merea
and to publish this model as Linked Data (among other forms). The purpose of its
ontology, then, is to provide a vocabulary that can be used to describe the model and
explain what the data is. The topographic model and the ontology are then available
for others. This means that the vocabulary should be of use not only to Merea Maps
but also to those using its Linked Data. Merea Maps therefore defines the purpose of
its ontology as follows:
To provide a vocabulary that describes the Features and the relationships between
them sufficient to enable the publication of topographic information as Linked Data
and to be understandable by others so that they may query our data.
The scope then follows from the purpose. The scope refines the purpose by limit-
ing the content to only those things necessary to fulfill the purpose. In terms of
classes, this is relatively easy as the ontology needs to define core classes that relate
to the Features that are surveyed by Merea Maps and the minimum set of secondary
classes required to describe these core classes. Specifying the scope of the relation-
ships is also done in terms of the minimal set of relationships required to describe
the core classes. Merea Maps therefore defines the scope:
To include all classes that describe the Features surveyed by Merea Maps and the
minimal set of other classes and relationships necessary to describe these Features.
So, for example, if Merea Maps' ontology builders were considering whether to include
the concept “University” in the ontology, then they could ask themselves, “Does it help
to describe the topographic features in our Linked Data set?” to which the answer
would be yes as Universities are shown on their maps. However, the term
University
itself is used ambiguously; it is used to refer to both the physical representation of
the university (the buildings, land, roads, etc.) and the organization—the legal entity.
Merea Maps' interest lies in the former not the latter. The description of the latter
concept would be primarily outside the scope of a topographical ontology. While the
University buildings are topographical features, the University as an organization is
not a topographical feature. So, by specifying the purpose and scope of the ontology,
Merea Maps' ontologists would be able to regard the University's physical manifes-
tation as the primary concept and the University as an organization as a secondary
concept and not add any details about the organizational features of the University.
10.4.2 c
ompetency
Q
Uestions
The level of detail of competency questions can vary. At their simplest, they can just
be a set of general questions to make sure that the purpose of the ontology is met and
that its scope is covered, such as, “Does the ontology include all topographic features
in Merea Maps' data?” However, a more detailed approach can be taken that has
