Cognitive Aspects: How People Perceive, Memorize, Think and Talk About Landmarks - Landmarks: GIScience for Intelligent Services - page 72

hypothesis landmarks anchor distinct regions in mental spatial representations,
called the reference region of a landmark. Spatial cognition research does not
yet offer a good understanding of the size of these reference regions, or tectonic
plates [ 51 ] . If in a configuration of similarly salient landmarks each object stands
for its neighborhood one assumption is that the neighborhoods form a partition
of space. For example, a mental visualization of “at the church” could include
every location that is closer to the church than to any of the other salient objects
around [ 238 ] . However, if the configuration changes such a partition must change
as well. Winter and Freksa [ 238 ] also demonstrate that context can be captured by
contrast sets of landmarks, which means that the configuration becomes context-
dependent, or reference regions change between contexts. Furthermore, salience of
entities is also weighted, and the influence of different weights on reference regions
is also not clear.
The distinction between reference points, or landmarks, and non-reference points
implies at least a two-level salience hierarchy. At least in theory there is no reason
to limit this thought to a two-level hierarchy only. While we are not aware of
any research documenting the observation of zooming through multiple levels of
salience, at least anecdotal evidence suggests their existence. For example, we can
easily distinguish global landmarks—those shared by everybody, tourist and local
alike, local landmarks—those short-term tourists would not know but which are
shared by locals, landmarks of specific groups among locals—e.g., those shared
within family, and private ones.
Hierarchies by Granularity
We are all familiar with containment hierarchies. It is the way we have learned
geography. Continents are aggregations of countries, and countries of states or
counties. Accordingly, western postal addresses locate an addressee on street level,
then on city level, then on country level. Such a hierarchical structure is established
by part-of relationships from an entity at one level to an entity at the next coarser
level of granularity. Salt Lake City is part of Utah, and Utah contains Salt Lake City.
Mental spatial representations reflect these hierarchies by containment relationships.
Developmental psychology has already documented the fundamental role of topol-
ogy for cognitive spatial abilities (Sect. 3.3.2.1 ) . Other literature identified a number
of classifications of spatial granularity that are motivated by human conceptions of
space (for reviews see [ 56 , 177 ] ).
A hierarchy by granularity, based on aggregation and abstraction, is indepen-
dent from hierarchies on detail or on salience. Two objects of the same level
of granularity can have very different salience. For example, the Guggenheim
Museum in New York is more salient than the buildings next to it along Fifth
Avenue, which are nondescript apartment buildings. Even more, an object can
be more salient than its container object, i.e., salience does not accumulate with
aggregation and abstraction automatically. For example, more people will confirm
to have experienced (physically or mediated) the Champs-Élysées than the eighth
Arrondissement of Paris, of which Champs-Élysées is part of.