Topic 2 Flashcards
fundamentally, a map is
a form of communication in which there is subjectivity and miscommunication is common
Anything in GIS deals with
representation
bias is at every step of the map making process and in every choice we make
two critical aspects of maps
knowledge is power!
KNOW YOUR AUDIENCE!
What is geographical representation?
among the olders and most important forms of human knowledge
graphical (maps and pictures)
verbal ( oral or written)
numerical (statistics)
Two key issues in geographic representation/communication
what to represent
how to represent it
(who are you trying to communicate with?)
Describe human imperfect knowledge
we do not know everything!
scientific knowledge is work in progress
can seldom establish who or what is correct
human made versus natural spatial phenomena
human made = usually discrete (buildings, roads)
natural = continuous
what is cognition
perception, thought process, memories, experiences, biases
everyone interprets things differently based on their personal views
things that are close to us are the most important
3 aspects of cognitive biases and representations
attaching importance
proximity and familiarity
cultural biases
why do certain symbols/words work
culturally significant - know your audience
describe and explain the cognitive map
cognitive maos are an internalization of everything we (individual) know and perceive
prior knowledge plays an important role
EX.
cog map at T0 + new experience (looking at map) = cognitive map at T1
describe the importance of shared knowledge in communication
in cartopgrahy there will usually be some overlap between map maker and map reader.
map maker must determine WHAT is that overlap
online access to geographic data and its issues
lethora of geographic data online, which dramatically changes how we can learn about people and places
Issue:
who controls this information
what are we not being told
describe the cartographic process (feedback loop)
an iterative process between the map maker and map user
describe the reality to cognitive map
reality - cartographers reality - map - readers reality
requires following actions
selection
generalization
classification
simplification
symbolization
describe NOIR groups
nominal - cannot be sorted (names)
ordinal - ranking between ranks does not matter (first, second , third)
interval - ranking between matters, zero IS arbitrary, can add/subtract
ratio - zero is NOT arbitrary, can do multiplication/division
describe the geospatial triangle
an object is connected by 3 primary things
attribute
location
time
what are the 4 general types of maps
reference
thematic
static
dynamic
map functions ranked
- navigation
- urban planning
- forecast (weather)
- management/storage or monitoring
- education
- legal maps - property lines
what are choropleth maps
commonly used to portray data collected from discrete spatial units
limitations
does not show variation within unit
boundaries are arbitrary
proportional and graduated symbol maps
scaling symbols in porportion to magnitude of data
proportional - unclassed quantitative, size according to specific value
graduated - distribute features into distinct classes
largest challenge is how to scale the symbol
isarithmic mapping
based on continuity of phenomena
isometric - true point data
isopleth - conceptual point data
collected in an area or volume but data is considered at local points
map use cube
public visual communication vs private visual thinking
cartograhic “rules” depend on your positon in the map use cube
what is your maps purpose?
power and privilege
maps are not objective - carry hidden agendas, can exploit or conceal information
situated knowledge - all knowledge is partial and uncertain
maps are taken for the truth, especially when they visually look good
designers have the power
what is an important factor for dynamic animated maps but not static maps
orientation
six basic visual variables
position
size
shape
orientation
patter
colour
describe gestalt
something that is made of many parts yet somehow is perceived as a whole
very critical for cartography
form, shape, whole
fundamentally important
works with figure/ground
figure/ground relationship
ways of accentuating one object over another based on human perception
stratified depth
based on contrast
briing important material forward
what is a graticule
network of lines on a gride
latitude/longitude
HSV & RGB
HSV - used for cartography (attempts to be intuitive and mimic the way humans see light)
RGB - not as much use, good for computer colour production (never use)
trichromatic colour perception
red, green, and blue in our eyes.
colour perception done in your brain (positive/negative effect)
CIE Lab
best model for how we perceive colour
3d, flexible model
spatial fallacies
locational
atomic/individualistic
ecological
MAUP
describe MAUP
key analysis of spatial data
human like geography
as you change boundaries between numerical units you can get different statistics
describe ecologial fallacy
use of spatial data about a group and apply it to an individual
describe individualistic/atomic fallacy
make decisions about a group based on an individual
nearly the opposite of ecological
describe locational fallacy
areas of the city summarizes household income but units are based on wok structure
Ex. darren income being included in UofC concensus rather than Tuscany
classification - univariate
mapping one variable
common misuse of data
optimal (fisher-jenks) most important (default class)
what are developable surfaces?
surfaces that can represent 3d mapping in 2d
plane
cone
cylinder
list and example for a conformal and equal area map
conformal - mercator
equal area - Wagner IV
Patterns of distortion (cylindrical)
tangent - touches globe in one place
secant - touches globe in two places
what is hypsometry (hysometric tinting)
used for elevation
how much of an area is at elevation
distribution of elevation
what are isolines
point data converted into continuous fields
what are hillshade models
models used ot show depth
can be unidirectional or multidirectional
colour ramp vs classed colour values
colour ramp = smooth gredation
classed values you can see where areas of colour start and end
bivariate and trivariate choropleths
maps two variables (bi)
maps three variables (tri)
hard for viewers
very advanced
nature of time maps
discrete mapping = linear time
continuous mapping = cyclic
web maps
static
dynamic
tiled maps - rapid zooming and planning
mashup - combination of multiple sources
describe the importance of static and longform visual stories
narrative, longform maps are everywhere, very popular, and often trusted and info is retained by viewers
