Database Reference
In-Depth Information
buildings being present. A Place is now either a kind of Site or a kind of Building.
Place has to repeat the intended Purpose as this is necessary to ensure that if a Place
is just a kind of Building, then it also has a Purpose associated with it.
10.4.4.4 Use and Purpose
This pattern for Place cannot be applied to all Features because while all Features
can be described in terms of the required parts, not everything has a purpose. What
is the purpose of a hill, river, or cave? All of these things can have uses but they do
not have a purpose (or at least not as a rule; it is possible that a specific hill, river,
or cave could be an artifice and have an intended purpose, but these are atypical
as most are natural landscape features). Here, the idea of
use
has been introduced,
and it can also be seen that artificial features can have uses: A school can be used
not only for educational purposes but also as a voting station, an emergency center,
and so on. Whether the Feature has a purpose or not, what is clear is that uses can
only be applied to particular and specific instances of things. We can say that a
particular river such as the River Adder is used for canoeing, but we cannot say all
rivers are used for canoeing. Similarly, the Merean government has allocated only
certain schools to act as emergency centers, not all the Merean schools. What this
tells Merea Maps is that it needs a new property “has use,” but unlike the property
“is intended for,” “has use” will not be used in statements within the Topographic
Ontology that it is developing, although it will be described as a property within the
ontology. This is because “has use” is only applied to individuals of classes, not to
classes themselves. Merea Maps also realizes that there is a relationship between
“has use” and “is intended for”; the latter is a subproperty of the former, and indeed
Purpose should really be renamed Use. To understand why it is advantageous to
form this relationship, consider a football stadium. We can say that all football stadia
have the intended purpose of leisure activity and more specifically playing foot-
ball; this also tells us that “playing football” is a subclass of “leisure activity.” Now,
a specific football ground, Medina Academicals Football Stadium, is also used as a
music venue, but this is not its main purpose; performing music is not what makes
a football stadium a football stadium—playing football is. Merea Maps can therefore
describe the Medina Academicals Football Stadium as follows:
Use is a Concept.
“has use” is a relationship.
“is intended for” is a special
type of “has use”.
Football Pitch is a kind of
Feature.
Leisure Activity is a kind of Use.
Playing Football is a kind of
Leisure Activity.
Performing Music is a kind of
Leisure Activity.
Every Football Stadium is a kind
of Place.
Class: Use
ObjectProperty: hasUse
ObjectProperty: isIntendedFor
SubObjectPropertyOf: hasUse
Class: FootballPitch
SubClassOf: Feature
Class: LeisureActivity
SubClassOf: Use
Class: PlayingFootball
SubClassOf: LeisureActivity
Class: Performing Music
SubClassOf: LeisureActivity
Class: FootballStadium
