|Using technology to interpret the world
makes data analyzation a much less time-consuming task than in the past.
Before the advent of the computer, each time one wanted to look at a different
data set, a brand new map had to be laboriously hand drawn.
Now, using a program as basic as Excel, we
can look at different factors that influence life around the world. Your
task will involve applying numerical data to a series of maps to get a
quick introduction to the power and capabilities of a GIS
Step 1: Obtain
a set of data.
Step 2: Open the
data in Excel. Look at the different columns. The first one should be the
country names. The others are the data for each country arranged by year.
Highlight the first column and whichever year you want to map.
Step 3: Locate
the map icon on the upper right toolbar. Click on it. Now go into the spreadsheet
again and click. This will start the mapping process.
Step 4: The first
step in the mapping process is called ‘geocoding’ (see your notes). The
GIS in Excel is matching the data you gave it to analyze with the information
it contains for the basemap. Some of the names will not match up correctly
and the program will "ask" for clarification. Tell the computer how to
interpret the data
For example, the first one that should pop up
for most of you will be ‘Central African Rep.’ The closest match the GIS
has for that name is "Central African Republic." Are they the same? Yes.
Highlight theat name and click "change."
Now, when a country comes up that should
be included, find the match for it and click ‘change.’
The program will go through and ask you about
all the inconsistencies between it and the data table. For " Yugoslavia,
Fmr" use "Federal Republic of Yugoslavia."
Step 5: Once the
geocoding has been completed, Excel will draw the map for you. You can
adjust the view you have of it by either dragging the corners or via the
Step 6: Look at
the "Microsoft Map Control" box. This is where you decide how you want
your data displayed. The most common options are value shading, dot density,
and gradated symbol. Click and drag the different symbols into the box
to see how each is displayed (and how each makes your map appear).
The "Symbol Option" page lets you change the
properties of the symbols or shading you’re using. Play around with different
values, # of categories, symbols, etc., to see how they change the look
of your map.
(Remember that when you print at school, you’re
most likely going to be using black-and-white, so keep that in mind. I
would suggest going to "map," "features," and removing the ‘oceans’ option.)
The "Legend control" page lets you label the
map as you’d like. Make sure your map has the appropriate labels on it.
Step 7: To print
your map, I still haven’t found a really efficient way other than to click
on the map, them select "edit," "copy," open a new workbook, and paste
the map in it. Do NOT try to change the map after you've pasted it. It
will not work and you'll lose the data that's already there. If you figure
something else out, let me know!
Assignment # 1:
Simply print out a map of the world
with a correct title (for example: World Population Density by Dave Stutz)
Assignment # 2:
Print out 3 maps of your data from
the same year using the same value range and # of categories: 1 value-shaded,
1 dot density, and 1 graduated symbol. Type up an analysis of the comparative
strengths and weaknesses of each map (what is good and bad about each).
Print out 2 maps: 1 from the first
year of your data and one from the last year. Analyze and explain the changes
Option: If you want, you can simply
subtract the last column from the first, map the difference, print out
that map and analyze the difference.
Print out 2 maps of the same year,
but try to make them imply completely different conclusions. Use different
symbols, different scales, different categories, etc.
One of the strengths of a GIS is
the ability to overlay different data layers, like putting overhead transparencies
atop one another. In this way relationships between different causes can
be inferred. Using a different data set for the same year, create
a new spreadsheet and map the two together.
You’ll need to copy and paste the data column
from one set next to the country and data columns from the other. Highlight
all 3 and start the mapping process
Now you’ll have the option to choose 2 different
ways to display the information on top of one another. Drag the column
you want to use (usually B or C) down into the map control and then choose
the type of symbol to use.
Unfortunately, because this is a real low-end
GIS, you don’t have the option of adding a whole range of textures and
shading on a map.
You can get some idea of the power of a graphical
display of information. It makes patterns that might not have been immediately
obvious more visible and easier to view (of course, as you’ve seen, it
also is very easy to manipulate the data to reach widely varying conclusions!!)