Transcript Lecture 20

Introduction to
Cartography
Russell Kirkpatrick
Jochen Albrecht
“When I get a little money
I buy maps;
and if any is left,
I buy food and clothes.”
–Desiderius Erasmus
What Is Cartography?
 Photography = making and study of
photographs
 Cartography = making and study of…. ?
So the real question is: what is a map?
What Is A Map?
A map tells you
where things are …
But so does a
satellite image …
What Is A Map?
Rockville
Baltimore
Columbia
City
City
City
A map tells you
what things are …
But so does a
gazetteer or a list …
What Is A Map?
The MAP
Formal Definition
“A graphic representation of the
location and attributes of phenomena,
in which spatial relationships can be
discerned.”
Cartography
Formal Definition
“The study of map making,
including every operation from
data acquisition and storage to
final display and use.”
Turning “Reality” Into a Map
A) Deconstitution of Reality
(the subject matter of the map)
1. Map Question
What do I want to find out?
2. Data Selection
Which data will shed light on the map question?
3. Data Acquisition
How do I gather the locational and attribute data I need?
4. Data Storage
How should the data be arranged for efficient retrieval?
Turning “Reality” Into a Map
B) Reconstitution of Reality
(the form of the map)
1. Projection and Scale
What scientific framework will the data be placed within?
2. Cartographic Elements
Which artistic elements will best represent the data?
3. Production
Which technologies will I make use of to produce the map?
4. Printing / Display
What media will be used to display the map?
1. Map Question
What do I want to find out?
In this example I am a free agent cartographer, and I
decide I wish to find out something about the
limitations of women’s use of the urban environment.
In practice this is most often dictated by legislation,
contract or business opportunity. Few cartographers
have the opportunity to select their own subject
matter.
The question I pose is:
“Where do city women spend their time?”
2. Data Selection
Which data will answer the map question?
“Where do city women spend their time?”
We can seek data on this question in a variety of
ways: for example, applying to register a Census
question; searching for the research results of others;
or conducting primary research of our own.
Limitations of time and the lack of previous research
in this area lead us to conduct our own research. We
limit the data collection period to one calendar month,
from three women only, collected in 15-minute units.
3. Data Acquisition
How to gather the locational and attribute data?
We contact three women who reflect a cross
section of ages and incomes. Gaining their consent
and promising to protect their privacy, we then ask
them to keep a diary for one month.
The women in our sample will account for each 15minute period of their waking hours, recording
where they are and how long they spend there.
4. Data Storage
How should the data be arranged for retrieval?
We record the
6000 data points
in raw form in a
spreadsheet, then
produce an
aggregate timeseries set sorted
by woman and
location.
5. Projection and Scale
What is the scientific framework?
A map projection is …
Map scale is …
In our example the base map is on a city scale
(approximately 1:50,000 to 1:100,000).
However, we will have difficulty positioning all the
data points at this scale, as many of them are close
to the woman’s home. The solution is to adopt a
flexible scale, in which distance between points
decreases from the map centre...
6. Cartographic Elements
What artistic elements represents the data best?
Cartographers use a wide variety of visual
resources, such as color, shape, line width, pattern
and typography to make their message clear and
aesthetically pleasing.
In our example weI face an ethical dilemma: cones
would be the best method of representing the
attribute data, but this would identify the location too
closely, thus breaking our privacy agreement...
…so we use circles, despite the ambiguity.
7. Production
What technologies to use for map production?
The technological revolution of the 20th century has
changed the way cartographers approach the task
of map making.
The advent of computers have made both data
capture and presentation easier in two main areas:
1. automation of previously manual tasks, thereby
saving time
2. providing the ability to experiment, making
cartographic visualization possible
8. Printing / Display
What media will be used to display the map?
In the past, the only method of display - and
therefore of communication - was printing the map
as a loose sheet, or bound with a report or atlas.
The widespread use of computers has led to an
explosion of ‘ephemeral’ maps, which appear on
screen only, never to be printed out.
Summary:
What is Cartography?
Cartographic Abstraction
leaving reality behind
Certain key decision-making points lead the map
away from the reality upon which it is based:





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Generalization of data
Classification of data
Reduction in scale
Transformation from a curved sphere to a flat
surface
Semiotics: the use of symbols
Derivation: inferring distance, direction, area,
proximity, connectivity etc. from the map
Map Types
different ways of categorizing maps

by Scale: large or small (the name applies
to the size of the fraction)

by Subject: soil, vegetation, transport, etc.

by Function: navigation, planning,
education, legal, etc.

by Form: choropleth, isopleth, dot
distribution, dasymetric, etc.
Cartographic
Communication
Why is Theory Important?
“I don’t believe in maps because it never looks like it
says on the maps when you get there.”
“How do people feel about maps? Only 14% of the
people in the United States claim to like maps. Even
people who claim to like maps use them only as a last
choice. Maps are a hassle.”
“Only 34% of map users are women, 39% of
households own no maps at all and less that half the
population referred to a map of any type during the
previous year.”
Why is the map message so hard to understand?
Theory

Up until now we have only considered
the makers of maps, and the maps
themselves

It is time to extend that to consider the
theory of cartographic communication

Theory is important because the makers
of maps are influenced by others in the
communication process
Two Fundamental Questions

Who are the people/agencies involved
in the cartographic communication
process?

How do they communicate? or
How is meaning transferred?
Models of Cartographic
Communication

Process Model

Semiotics

MUGs Model
The Process Model
signal
Information
Source
Transmitter
Noise
Receiver
Destination
Noise
Source
Process Theory devised by Shannon and Weaver,
Bell Telephone Laboratories, to maximize efficiency
of electronic communication in World War II.
Process Theory
Identifies

sender (cartographer) and receiver (map user)

signal is the map message

encoding by cartographer

decoding by map reader

noise (designer/reader) is interference with
perfect communication
Criticisms of Process Model
Electronic analogy does not hold for real-world
communication:
 communication may not have taken place
 one-way communication to a passive map
user
 noise’ used as an explanation for all
communication problems
 it has no social context
“If a person speaks gibberish into a telephone, and it is clearly
audible to a listener, then the communication system is working
perfectly. It is, however, questionable whether and
‘communication’ has taken place.”
Keates, 1982
Semiotics
Map maker



Designation
Semantics
Sign
Vehicle
Connotation
Pragmatics
Map user
Semiotics is the study of signs and how they symbolize
ideas
Communication takes place when the communicator
constructs a message out of signs (semantics) and passes it
on using a ‘sign vehicle’ - in this case a map - to an
audience, who use their knowledge of the code and their
social context (pragmatics) to reconstruct a message.
Interpretation is a matter of what connotation the interpreter
places on the designation of the communicator.
Strengths of Semiotics
Map maker



Designation
Semantics
Sign
Vehicle
Connotation
Pragmatics
Map user
Concerned with encoding and decoding of concepts
The map user plays an active part in the process
Shows how misunderstanding might occur – the use
of different ‘code books’ by maker and user
“A sign system only functions because the creator and the user
attempt to agree on the meanings of the signs and their
relationships. A great deal of education is directed towards the
goal of ensuring that signs are correctly interpreted and
understood.” Keates, 1982.
Criticisms of Semiotic
Theory

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The code analogy does not explain how two people
viewing the same sign and aware of the same
codes might interpret that sign in different ways.
Blames the map user for not understanding the
work of the map maker.
Reductionism: the research separates subject and
object, assessing the subject’s responses to stimuli
divorced from social and environmental context.
“The impression frequently given is that the experimental
subject is a sensitized screen on to which the researcher
projects some cartographic material in order to measure
the result.”
Griffin, 1983
Criticisms of Cartographic
Theory

How and why map messages are generated
has not been addressed

How maps are made is not fully explained

How the map message is received and
interpreted is misunderstood

The social context of cartographic
communication is ignored

The transfer of meaning has never been
explained
Map Generation
The Myth of Cartographer Generation

Map makers are the ones theorizing. They
consider themselves the initiators of
cartographic communication. Maybe in
academia, but not in the real world.
“Behind most cartographers there is a patron; in innumerable
instances the mapmakers were responding to external needs.
Monarchs, ministers, state institutions, the Church, have all
initiated programs of mapping for their own ends.” Harley, 1989.
Map generators are those people or agencies who are
authorized to initiate the production of a map.
Map Making
The Deconstitution and Reconstitution of Reality
Map Users
Targeted and Non-targeted

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Maps that are produced for a specific
purpose generally have a narrow audience.
Those that cost a large amount to produce
are often marketed to a wider audience
The result is that the map user base is
widened beyond those originally targeted by
generator and maker
The consequences can be summarized in the
principle of eavesdropping
Map Users
Targeted and Non-targeted
The MUGs Model
Sent to
G
M
Generator
Maker
Sent to
and
Sought by
Sought by
U1
Original
Targeted User
U2
Newly
Targeted User
U3
NonTargeted User
The Social Context of
Mapping

Maps have evolved in a western culture
which is impositional in nature. They
have not evolved in a social vacuum.

Maps have been used as instruments to
exploit resources and control people.

This social context must influence every
step of the process of cartographic
communication.
The MUGs Model
Deals with 4 of the 5 problems
Recommendations
Generator
Brief
G
M
Feedback
The Map
no direct
communication
Social Context
U
M
Recommendations
G
Generator
Brief
The
Prescription
Feedback
The Map
1950: 1st ed. 1:63,360
1986: 2nd ed. 1:50,000
U
Newly
Targeted
no direct
communication
Targeted
Defense
Department
'serious'
map user
Nontargeted
others
Transfer of Meaning

Relevance Theory developed for verbal
communication

The theory is more flexible and less
predictive than others
Concepts in
Relevance Theory
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Face
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Ostention

Manifestness

Inference

Relevance
Concepts in
Relevance Theory
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Face
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We use words to save face for ourselves or
for others. The ritual apology which everyone
knows is insincere nevertheless saves face.
Maps are a ritualized, one-way interaction
ritual between egocentric selves
The generators of map communication seek
to impose their ideas on others, known in
Relevance
Theory as a face attack
Concepts in
Relevance Theory

Ostention

An ostensive act signals to the audience the
intention to communicate

Advertising is a blatant form of ostention
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Maps are not very good at this!

The title of a map is usually the ostensive act
Concepts in
Relevance Theory

Manifestness
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
How can map generator, maker and user share
contexts when they never meet?
We assume common experiences will make the
intention of the communication manifest
Maps tend to have many things weakly
manifest compared to other forms of
communication
Concepts in
Relevance Theory

Inference

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Map semiotics can be ambiguous, so to
recover meaning we infer from the context of
the map and our experiences
Maps are made up of inferences and
abstractions


e.g. contour lines to infer elevation
We use a process of suitably constrained
guesswork to infer meaning
Concepts in
Relevance Theory

Relevance

Relevance = effect – effort

High relevance is maximum effect for minimum effort

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Marginal relevance is high effect/high effort or low
effect/low effort
Irrelevance is minimum effect for maximum effort
Because maps are weakly manifest, the effort
required is usually high
The Principle of Relevance
“Every act of ostensive communication communicates
the presumption of its own optimal relevance.”
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The generator implies that the information on a
map is relevant
The map maker tries to make the message
manifest
The map user continually tests this using their
individual criteria of effect and effort
Deception occurs when impositional
communication is used;
this is how we lie (including with maps).