Cognitive Aspects: How People Perceive, Memorize, Think and Talk About Landmarks - Landmarks: GIScience for Intelligent Services - page 82

3.4.2 Sketches

A sketch, in contrast to verbal language, is a pictorial representation. We con-
sider here sketches describing spatial locations, spatial configurations, or routes
through an environment. These sketches convey visually a subset of a mental
spatial representation, filtered for relevance, abstracted, schematized and mostly
qualitative. A prime example of sketches are subway maps, which are highly
schematized, and adhering to network topology rather than geometry. People also
sketch in everyday situations and with much less rigour to schemas, often quickly
drawn on a napkin. Studying sketches has become a standard method in spatial
cognition research to learn about the individual's mental spatial representation.
Sketches produced by humans contain also all the cognitive distortions of mental
spatial representations [ 52 , 232 ] . The scientific approach of asking people to draw
is acceptable since test-retest experiments have shown that people produce highly
correlated sketches over time [ 10 ] .
Already Lynch asked people to draw sketches of their home town [ 128 ] . Lynch
was interested in the legibility of cities, or in the ease of conceptualizing the
familiar layout of the city in internal mental spatial representations. Thus these
sketches can be understood as direct externalizations of the participants' mental
spatial representations, although focused on the communication context set out by
Lynch's instructions. Lynch observed that these sketches contain mainly five types
of elements. He identified paths , edges , districts , nodes ,and landmarks .Theseare
the (shortened) definitions provided by Lynch ([ 128 ] , p. 47)—examples in italics
added by us:

1. Nodes are points, the strategic spots in a city into which an observer can enter,
and which are the intensive foci to and from which they are travelling. They
may be primarily junctions, places of a break in transportation, a crossing or
convergence of paths.
Think of a busy street intersection or a popular place in the city center.
2. Landmarks are another type of point-reference, but in this case the observer does
not enter within them, they are external.
Think of a store, a monument, or a school.
3. Paths [are] channels along which the observer [...] moves. [...] they are the
dominant elements [of a city] image. People observe the city while moving
through it, and along these paths other environmental elements are arranged and
related.
Think of roads, trails, sidewalks, or underground passages.
4. Edges are the linear elements not used or considered as paths. They are
boundaries between two phases, linear breaks in continuity.
Think of walls, seashores, or railway embankments.
5. Districts [...] are sections of the city, conceived as having two-dimensional
extent, which the observer mentally enters 'inside of', and which are recogniz-
able as having some common, identifying character. Always identifiable from the
inside, they are also used for exterior reference if visible from outside.
Think of a wealthy neighborhood, a business district, or a nightlife quarter.