GeoNet 3: Data Sets
by Patrice St. Peter
After this lesson, students will be able to:
(Numbers below correspond to the Minnesota State Learner Outcome List in geography.)
2. Identify and define conventional map symbols.
9. Read and understand the symbols used on thematic maps (e.g., find the height of the
ground from a layer-tinted map; interpret simple relief maps; read heights and identify
slopes, hilltops and valley floors).
14. Describe a distribution shown on a map in terms of density, directional alignment,
spatial concentration, gradients and pattern.
15. Interpret pictorial, shaded-area, proportional-symbol, isoline, choropleth,
flow-line maps and cartograms.
20. Explain some of the factors that influence the choice of projections for particular
mapping tasks (e.g., equal-area for population distribution).
21. List some major sources of geographic data and briefly describe their
characteristics (e.g., aerial photographs, satellite images, field surveys,
topographic maps, census records, statistical abstracts, almanacs, questionnaires).
22. Identify the major kinds of symbols used by cartographers and describe the kinds
of data these symbols are usually used to depict (e.g., pictorial symbols, graduated
circles and other proportional shapes, dots and other repetitive symbols, nominal
lines, flow lines, shaded areas, and choropleth shading).
23. Explain some ways in which a cartographer can transform data to make it more
useful for a particular purpose (e.g., calculating percentages of a total,
densities per unit of area, values per capita, or other ratios of several kinds of
24. Describe key aspects of the human visual system and show how some kinds of
optical illusion can affect the way people see maps (e.g., red colors for emphasis,
upper-left focus for important ideas, weak grays to minimize clutter in background
25. Identify some ways in which a cartographer may intentionally or accidentally
mislead a map reader (e.g., colors that a significant fraction of the population
cannot discriminate, projections or symbols that distort in order to persuade).
26. Outline the basic components of graphic communication.
28. Classify geographic data into categories for further analysis or graphic display.
This involves selecting criteria for classification and then applying those criteria to
put individual observations into appropriate groups.
30. Select appropriate charting or graphing techniques for the display of information
about a place [e.g., a) Pie or bar charts to show proportions of various features in a
place; b) line or bar graphs to show trends through time in a place; c) bar graphs to
show comparisons of several places; d) line graphs to show differences from one place
to another; e) scatter diagrams to show relationships among features in a place; and f)
graphical analyses to identify exceptions to rules about places].
37. Create a well-designed map layout that includes the title, scale, orientation,
and relative location in the surrounding area (e.g., city, state, country, or globe).
Time Needed: 1-2 class periods
Overview: Students will order data to be used to create a histogram and a
thematic map. This is lesson three in a unit of four lessons that, when used together,
comprise a several day unit on cartography.
Objectives: Students will be able to:
1. Produce a database on the computer.
2. Rank order data electronically.
Data Sets (one data set per student)
Interesting data sets may be found in the following reference materials:
1. Statistical Abstracts of the United States
2. Publications of the Childrens Defense Fund
3. Kids Count, published by the the Annie Casey Foundation
4. Statisical Records of Children, by Gale Publishing Inc,
5. Any one of the several Almanacs published in the United States
6. The State and Metro Area Data Book of the United States, published by the United
1. Select data sets that will be interesting to your students. Make copies of the data
sets for each student in the class.
2. This lesson assumes that you and your students will have access to a computer lab
with machines equiped with a word processing package that includes a data base
function. Be sure that these resouces are available and that you or the computer lab
staff is prepared to instruct students in how to make and use data bases.
3. The lesson can be done by hand without losing any of its value, but it will take
longer for the students to make their histograms.
1. Handout individual data sheets to each student. Each student should have a
different data set. Students cannot lose this data set, because each student is the only
one being assigned that particular data set to map.
2. If you have access to a computer lab, follow step 3a. If you do not, follow step 3b.
3a. Using your word processing software (MicroSoft Works, Claris Works, etc.) produce
a database. Field One will be STATE NAME and Field Two will be DATA or a brief
description (e.g., POVERTY RATE). Students enter data. This will take an entire class
period for most students. Students who work quickly can add fields (e.g., state
abbreviation, state capital, etc.) to their database for extra credit or help others
finish their databases. If working in pairs, one student can enter the data while the
other student reads off the numbers from the data sheet.
When students finish entering data, they should format fields, decide to order data
from ascending or descending order. Students should put a HEADER with their name
and a title for this database. Print databases.
This rank ordered list can be used to make their histogram. They should then make a
histogram following the procedure used in GeoNet Lesson 2: HISTOGRAMS.
3b. Students without a computer will use the data set provided to them and put the
information onto a grid sheet to make a histogram. There are no real short cuts in this
process. They will have first look at all entries. Once the have an idea of the range,
they should use one of the grid sheets to make a histogram following the process used
in lesson 2.
4. Students must get your approval on the Classification Scheme. Check their
histograms before allowing them to go to the map making steps.
5. Students should study their finished histogram and produce a classification scheme
of categories for their maps. You will be able to help students do this if they are not
yet confident in being the real map-maker. The category break-down can have an
influence on the spatial pattern for the finished product. Most cartographers favor the
̉NATURAL BREAKS classfication scheme because it reflects the natural spatial
distribution. However, some data sets lend themselves well to even (e.g., by 10s, 20s)
or equal (e.g., quartiles) categories.
Evaluate students classification schemes, histograms and maps.