Cognitive Aspects: How People Perceive, Memorize, Think and Talk About Landmarks - Landmarks: GIScience for Intelligent Services - page 88

Later Streeter et al. [ 207 ] applied a pure navigational performance test to com-
pare customized route maps with verbal route descriptions. They demonstrated that
car drivers following the verbal route descriptions, which provided one instruction
per turn, drove fewer miles, took less time, and showed about 70 % fewer errors
than the drivers relying on the route map. If a picture tells more than 1,000 words
then less is obviously more. Correspondingly, drivers who had both verbal route
descriptions and the route maps available performed badly as well.
Then Denis and collaborators [ 37 - 39 ] collected campus route descriptions from
students. They applied all four approaches in their study of these route descriptions.
In later work [ 40 ] Denis et al. repeated the experiment in the real world, collecting
route descriptions from citizens of the city of Venice, and confirmed the prior
findings.
First, they characterized the collected route descriptions by criteria such as
actions specified and localized by a landmark, actions specified without a reference
to a landmark, references to a landmark without any specified action, descriptions
of a landmark, and comments. Results documented that people with higher
visuo-spatial imagination also use more landmarks in their descriptions, which
supports our claim that landmarks bridge between visual memory and spatial
memory.
Secondly, these instructions were rated. The rating was performed by local
experts and non-experts.
In addition, and related to the fourth approach, they came up with a construction
of minimal descriptions, which they call skeletal descriptions. For the construction
they used the elements identified in the student generated route descriptions, thus
maintaining the perspective taking of the speakers whilst concentrating on the
smallest common denominator in the descriptions.
And fourth, they tested navigational performance of instruction followers
equipped with good, poor, or skeletal route descriptions.
Three of their observations are critical for us:

￿ The construction of skeletal descriptions confirmed that “landmarks and their

associated actions were key components of [good] route description” ([ 39 ] ,
p. 409). Also, references to landmarks are unevenly distributed along the route.
They tend to concentrate at points where orientation decisions are to be made.

￿ Rating of the original route descriptions is highly correlated with their similarity

to the skeletal description.

￿ Skeletal descriptions received scores similar to those of good descriptions,

despite being, on average, shorter by design.

Independently, Lovelace et al. [ 127 ] collected a corpus of route descriptions for a
particular route, and then searched for shared characteristics such as numbers of
segments or turns, or numbers of references to landmarks used. Their classification
schema was inspired by Denis' et al. but further refined by grouping landmarks in
those at decision points and those not at decision points. While Denis et al. report
of a tendency for concentration of landmark references at decision points, Lovelace
et al. find about half of the landmark references not at decision points. Considering