Module 5 Cartography, GEOG EXAM
If a map is nominal data, it is:
a qualitative map
color lightness can imply:
an increase in quantity using the darkness of the color dark blue indicates higher magnitudes than light blue
Pictographic symbols
can be used for point feature maps designed to look very similar to their real-world counterparts
interval data
consists of numerical values on a magnitude scale that has an arbitrary zero point numerical value can order from low to high with a numeric difference between the classes ex: land elevations Numerical intervals between values are meaningful but ratios between two values are meaningless ex: Fahrenheit scale for temp -equal differences on this scale represent equal difference in temperature ex: temperature
If you classify data based on what kind of geographic phenomena the data represents it will be __________________ or ______________, or ________________
continuous or discrete or point, line, area, or volume data
what are the two levels of measurement that are quantitative
interval ratio
maps show us _______ NOT _______
maps show us DATA not phenomena
example of topographic map
maps that have irregular curves that represent elevation, lakes, etc.
nominal from the video
most basic level of measurement categorical or qualitative ex: sex, color, chocolate preference frequency or percentage cannot calculate anything pie chart, column or bar chart
interval/ratio from the video
most precise can be measured number of customers, weight, age, size scale, quantitative, parametric can be discrete or continuous mathematical versatile bar chart or histogram
example of volume phenomena
mountains and ocean trenches
what are the two levels of measurement that are qualitative
nominal ordinal
If you classify data based on levels of measurement. It will be ______, ______, _______, or _____ (Here a measurement level describes the nature of numerical info about geographic features)
nominal, ordinal, interval, or ratio data
volume phenomena
occupies a volume in space (including lengths, width, and depth) at the scale of the map
area phenomena
occupies an area on the map such as houses, forests, lakes, counties, and even buildings at a large enough scale
T/F qualitative maps AND quantitative thematic maps can both be classified as single-theme maps or multivariate maps
TRUE
what is an example of a thematic map
US poverty levels in 2010 coloring of counties by the percent of people under the poverty line
flow maps show transportations spatially using a line symbol called:
a flow line
isoline maps
a line on a map or chart alone which there is a constant value as of temp or rainfall or average daily solar radiation thematic map
choropleth map
a map that uses differences in shading, coloring, or the placing of symbols within predefined areas to indicate the average values of a property or quantity in those areas thematic map
Dot density maps
a map type that uses a dot symbol to show the presence of a feature or a phenomenon thematic map
If a map is ordinal, interval or ratio data it is:
a quantitative map
color saturation/ color intensity can imply
a subtle visual variable that is best used to show subtle variations
qualitative change map
a type of map that shows the change in geographic phenomena display changes that are qualitative/categorical rather than quantitative
level of measurement
a way to describe the scaling of data in statistics four levels nominal ordinal interval ratio
example of a reference map
a world map shows the boundaries of continents, oceans, and countries, their names, as well as important water bodies
Discrete phenomena change _______
abruptly nothing in between
Mimetic symbols
can be used for point feature maps symbolize between geometric and pictographic symbols they are often created from a combination of geometric shapes ex: mimetic symbols are on tourist, recreational, and airport maps
geometric symbols
can be used for point feature maps use simple shapes such as squares, circles, and triangles to represent features need a legend to be interpreted correctly
single theme maps for quantitative data
can depict point, line, area, and continuous surface features or phenomena point feature maps -proportional and graduated symbol maps line feature maps -flow maps area feature maps -choropleth maps -cartograms -prism maps continuous surface maps -isoline/isopleth maps -dot density maps -3D perspective maps
what is another word for discrete data
categorical data often represents objects
what are the three types of qualitative changes
change in the category of features over time at the same location change in the location of a feature over time show a time series of maps side by side that cover the same area and use the same symbols and legend
For qualitative maps we use the visual variables:
color hue orientation shape
ratio data ratio level data
consists of numerical values on a magnitude scale IN CONTRAST TO INTERVAL LEVEL DATA the zero point is NOT arbitrary the zero point is clearly defined and typically the zero point denotes absence of the phenomenon ex: thematic maps showing population density or anything other density, annual precipitation, crime rate, tree heights, tax rate, family income ratio level data have all the properties of interval level data but IN ADDITION it also has a natural zero value when the variable quals 0.0 there is none of that variable ratios between two values are meaningful ex: height, weight, or measurement of time
what is an example of area phenomena
counties are areas/polygons
Orientation is used to
create patterns that show qualitative differences for features. ex: a tree symbol oriented north or east can show whether the tree is dead or alive
disadvantages of proportional/graduated symbols to map quantitative data
densities/ratios/rates are hard to display with this type of map hard to tell different circle sizes apart especially when a continuous sequence of symbols have been used human eye can't differentiate between slight variations in symbol size
single theme maps
depict only one theme (i.e. one attribute at a time) at a time. This means only one column in the attribute table will be displayed on the map
multivariate maps
depict the geographical relationships between two or more phenomena show the relationship between multiple attributes -combined mapping methods -point symbols -charts
quantitative data
depicts the magnitude of things expressed in numbers (e.g.: size, importance) such data can be quantified, measured, compared, and taken a mathematical average of
quantitative thematic maps
describe any numerical information about spatial features and their relationships answer questions like: how many, large, wide, fast, high, or deep things are using ORDINAL INTERVAL RATIO data
line phenomena
describes features that follow a line without a defined width at a certain scale
point phenomena
describes things like houses or cities, which may be too small to be represented by areas or polygons on a map for a given scale
Map symbols with different sizes imply what
differences in quantity larger circle: implies greater quantity than smaller circle wider line: indicates a larger quantity than a narrower line more volume: indicates a greater quantity
Different shapes imply what
differences in type rather than differences in magnitude
color hue simply means
different colors symbols with different hues imply differences in quality or type green tree= alive brown tree= dead
Data describing the geographic phenomena could be _____ or _______
discrete or continuous
examples of continuous surfaces or continuous data
elevation aspect slope radiation levels from a nuclear plant and salt concentration from a salt marsh as it move inland
T/F Generally, vector data model is suitable for representing continuous geo-spatial data while raster data model is suitable for representing discrete geospatial data.
false Vector data model is more suit for representing discrete geospatial data, such as a point, a line or a polygon. Raster data model is more suitable for representing continuous geo-spatial data, such as terrain surface.
T/F it is okay to compute standard deviation using ordinal data
false Standard deviation cannot be computed using ordinal data which only contain the information of order (deduction and average operator cannot be applied).
T/F? One can measure the width of a line symbol on a map and tell the actual width of the corresponding line feature on the ground
false the width of a line symbol is rarely used to indicate the actual width of the corresponding line feature on the ground. instead the width is usually used to differentiate the classes of line features (ex: mainstream vs tributaries)
single themed maps -line feature maps *flow maps
flow is defined as the movement things from one place to another such as migrations of people, spread of disease, shipment of goods between regions flow maps show transportations spatially using a line symbol called a flow line
Single themed maps -point feature maps *proportional symbol and graduated symbol maps
for point features proportional and graduated symbols are commonly used to show quantitative information proportional maps use symbol size to represent the data value graduated maps use symbol size to represent groups of values (quantitative values are grouped into intervals, and all the features within a class are shown with symbols of the same size)
nominal data
has no order and only gives names or labels to various categories consists of categories used to distinguish different types of features values in nominal data are used to distinguish one features from another QUALITIES not quantities examples: gender, religion, political affiliation, college major, jersey number not always descriptive, could be stored as words or numerical code (ex: social security numbers, zip codes, and telephone numbers)- no numerical meaning NO ORDER ex: jersey numbers in basketball although numerical are measures at the nominal level the number does not imply order
What are some ways you can classify data
how the data is organized in digital format what kind of geographic phenomena the data represents how the data defines or describes the geographic phenomena levels of measurement
example of point phenomena
in a world map of major cities, each city is represented as a point
Ordinal data
includes values with order which allows comparisons of the degree between two values examples: scale of tree size (S, M, L), level of pain (1-10), movie ratings (1-5 stars), scale of hotness (hot, hotter, hottest) meaningful order but the intervals between values are not necessarily equal -ex: the gap between hot and hotter may be small whereas there might be a big discrepancy between hotter and hottest ordinal data are also considered to be categorical or QUALITATIVE still no quantifiable numeric difference between their values show position in rank such as 1st, 2nd, 3rd but they do NOT establish magnitude or relative proportions
why is mapping change difficult
it can be hard to find symbols explicit enough to convey the correct information to the reader
examples of qualitative data
land cover types soil types language and religion major in college education level name of major cities in the world non numerical in nature cannot take the average of anything
isochrones
lines of equal time difference (ex: show the range of the ash at different times 3 hours, 6 hours, 9 hours)
How can you tell the difference between proportional and graduated symbols
look at the legend if there is a range of data values (aka: 10,000-20,000) it is a graduated symbol map in a proportional symbol map- symbols on the map could have a size not listed but in graduated every size must be listed
Phenomena are... Data are...
phenomena are all the stuff in the real world data are records of obersvations of phenomena
what is point data used to depict
point phenomena
what is an example of quantitative data
population density and annual rainfall population in poverty of each county in the IS expressed as a quantity air temperature
Qualitative data ________ things, quantitative data ________ things
qualitative data DESCRIBES quantitative data MEASURES
if you classify data based on how the data defines or describes the geographic phenomena it will be __________ or _________-
qualitative or quantitative data
qualitative data shows what quantitative data shows what
qualitative shows the types/categories of features quantitative data shows magnitude of features/attributes
Pattern textures can imply:
quantitative differences by density a finer, more tightly-packed grid is higher in quantity than a loose, coarse grid
data that are qualitative examples
racial composition of a country rank of GDP of a country land cover types
ordinal from the video
rank satisfaction fanciness meaningful order but the values between the numbers are not equal (EX: more space between second and third than first and third) can be given as frequencies column or bar chart
ex of ratio data: ex of ordinal data:
ratio- groundwater storage water depth in mm 0-50,000 ordinal- aquifer productivity very high-very low
What are the two types of maps that are important to both geographers and the general public
reference maps topographic maps
single theme maps -area feature maps *choropleth maps
represent quantitative properties of AREA features by varying the lightness or intensity of color typically show density or rate information about area features (ex: counties, states, countries, etc.) such as population density or tax rate, rather than totals
continuous data
represents continuous phenomena which have no defined borders but a smooth transition from one value to another
discrete data
represents discrete phenomena with distinct boundaries a district, houses, towns, agricultural fields, rivers, highways are good examples of discrete phenomena
categorical data
represents objects these objects usually belong to a class (ex: soil type), a category (ex: land use type), or a group (ex: political party) these are known as categorical objects
example of line phenomena
river or road map
proportional symbol map
scale the size of simple symbols (usually a circle or square) proportionally to the data value found at that location. the larger the symbol the MORE of something exists at a location thematic map
advantages of using mimetic symbols compared with geometric or pictographic symbols:
self explained and require little work on building map legend can be wither simple or complex when representing real world features
What are the visual variables that effectively display qualitative differences?
shape orientation color hue
advantages of proportional/graduated symbols to map quantitative data
show data occurring at points show absolute values and precise numbers circles can be subdivided to show percentages of the whole easy to make
qualitative data
show the categories of things expressed by means of a natural language description
reference maps
show the simplest properties of geographic features in a specific area such as political boundaries, roads, water bodies, and cities
thematic map
shows one or a few themes of information fro a specific area which is often coded, colored, or grouped for convenience
topographic map
shows topological features including terrain elevation, water networks, boundaries, roads, towns, cities, and labels showing the names of important features. A TYPE OF REFERENCE MAP
For quantitative maps we prefer visual variables that can effectively impart the magnitude of phenomena to the reader:
size pattern texture color lightness/color values color saturation/intensity
point phenomenon
something that occurs at a point in space defined solely by a geographic location without width or area at the scale of the map
qualitative maps describe what
the location or distribution of a phenomenon and use nominal data
on flow maps the size (width) of the flow line is proportional to what
the magnitude of the flow magnitude of flow can be shown by varying texture color saturation and color lightness of the lines
quantitative maps describe what
the magnitude or value of a phenomenon and use ordinal, interval, or ratio data
Thematic maps usually describe what
the physical social political environmental and cultural properties of defined areas
What do single theme and multivariate maps have in common
they both use points, lines, and areas to display features
When do you use proportional symbol/graduated symbol mapping
total populations total production and sometimes derived data (densities, rates) of regions DO NOT map derived data with proportional/graduated symbols proportional/graduated usually imply magnitude rather than density or rates
Mappable data can be qualitative or quantitative T/F?
true
point feature maps
use symbols which show the location of an object. The point symbols can be geometric, mimetic, or pictographic
If you classify data based on how the data is organized in digital format it will be ________ or _________
vector or raster data
Almost everything in the real world is a _________ to us
volume
In multivariate maps how do you represent each attribute/phenomena
with a different symbol
Continuous phenomena such as air temp, precipitation, and elevation vary continuously without _________ _________
without incremental steps ex: temperature changes continuously from 66 to 66.01 there is always something in between two values of a temperature
