Throughout the term you have learned various basic skills; now you'll apply them to a research projec you design. You've probably seen indexes like that in Rand McNalley's Places Rated Almanac , or formulas to find best vacation places, best retirement places, etc. (try this site for some on-line "place selectors"). Unless you'd like to design your own (similar) study, you'll use digitized layers prepared by other 391 classes, and other layers you contribute, to find your favorite place among the 26,000 places in the lower 48 states. You'll also have access to census data for the entire U.S., at the tract, place, city, Metropolitan Statisticl Area (MSA), county, and state levels. You also have the skills to create a new spatial layer by digitizing or geocoding, adapt an existing spatial layer such as .dlg or TIGER, or information available on the Geography Network, or join a non-spatial attribute table to an existing layer.
STEP ONE
PRINT THE WORKSHEET: http://www.neiu.edu/~ejhowens/391/indxform.htm
You can use this to jot down and work out your ideas.
| CONCEPTUAL | REASON | REQ/PREF |
| Among educated people | It's important to have a community that is intellectually stimulating | REQ |
| In a racial/ethnic mix | I enjoy exposure to other cultures | PREF |
| In a temperate climate | I don't like extreme heat or cold; I like mild weather | REQ |
| Near family/friends | The easier it is to visit my family and friends, the better | PREF |
| Near an ocean or large lake | I find large bodies of water calming | REQ |
| In a middle-income area | I'm middle income and I'd like to be like others like me | PREF |
| In a place with low cost of living | Affordability | REQ |
| Where housing is inexpensive | I'd like to buy my own home | REQ |
| Where the crime rate is low | I'd like to raise a family and need security | REQ |
| Average population density | I don't like congestion but don't want to feel isolated | PREF |
| Requirements are the kinds of things you select by condition,
location or by combining selections. Each place will either qualify
(YES) or will not qualify (NO). Applying them will result in a selected
set. Here is an example of a requirement: "I must be
at least 100 miles from a major urban center," (anywhere beyond
that is fine, less than that, unacceptable). Other requirements:
a temperate climate zone, in Illinois, in Gerreau's bread basket, a town
between 5,000 and 30,000 people or a county with a moderate population
density.
Preferences are not a simple matter of YES/NO; rather thay are BETTER/WORSE. The preferences will be applied to those places which remain after all the requirements have been applied. Preferences will be used to index the qualifying places. Here are some examples of preferences: "the warmer the winter, the better," (refer to heating degree days), "the closer to Chicago, the better," (refer to a distance from Chicago variable), "the better educated the better," (refer to percent over 25 with a college degree). Avariable which you use as a requirement can also be used as a preference. For example, "I must live within 100 miles of an ocean, but within that zone, the closer to the ocean, the better." You'd use a condition "within 100 miles of ocean" to eliminate all nonqualifying places, and then a weighted formula (see below) to factor in distance-to-ocean for each qualifying place. |
Come up with a long list of things you like or do not like.
| CONCEPTUAL | OPERATIONAL | SOURCE | LAYER |
| Among educated people | Greater than 50% of adults have some college | Census data | Place |
| In a racial/ethnic mix | Absolute Value of 60-<percent white> | Census data | Place |
| In a temperate climate | Any "C" Koppen Climate | G&ES 391 | Climate layer |
| Near family/friends | Distance from county centroid to Chicago Centroid | PREF | County and CityPoint |
| Near an ocean or large lake | Within 50 miles of coast or Lake over X sq. miles in size | G&ES 391 | Coasts |
| In a middle-income area | Percentage of households between 50-75,000 annual | Census data | Place |
| In a place with low cost of living | Cost of Living Index (MSA only)* | G&ES 391 | MSA |
| Where housing is inexpensive | Average value home | Census data | Place |
| Where the crime rate is low | Low violent crime rate per 100,000 | G&ES 391 | MSA |
| Places with an average density | ABSValue(Ideal density - County population density) | Census data | County |
*Any data available by MSA can be transferred to all places in that MSA. This presents two problems: (1) places outside an MSA have missing information -- hence MSA data should be used only when a requirement is that it MUST BE IN AN MSA. and (2) all places within a particular MSA will have the same score for that variable. Hence, do not use more than one MSA variable, or you'll be ranking MSAs and not places.
The requirements, which require a QUALIFY/DISQUALIFY result are in regular
type. They require a specific characteristic or threshold to result
in YES or NO for each place. The preferences are not qualify/disqualify
but each receives a specific value or score. In making this list,
refer to the list of layers already prepared (below) and think about what
you might be able to contribute.
| The following layers are ready for your use. In some cases, they are incomplete (where noted). | |
CARTOGRAPHIC LAYERS -- probably most useful for display
|
|
NATURAL ENVIRONMENT
|
|
HUMAN ENVIRONMENT
And from Maptitude geographic CD for the U.S. (convert to Shape with Maptitude if it hasn't been done)
|
| PREFERENCES | RATING |
| Close to parents' home | 5 |
| Near Coast | 8 |
| Higher income area | 6 |
This will give him "percent of females aged 25-34 who have never been married". Or you might prefer
This will give him an eligible female / eligible male ratio, which incorporates male "competition." For another example, if you are concerned about population density, you might try either
for a straighforward measure of per square mile density..., or get a little creative with
(([HU RentOcc 5-9 HU] + [HU RentOcc 10-19 HU] + [HU RentOcc 20-49 HU] + [HU RentOcc 50+HU])/[HU Renter Occupied]) *100
In any case, use calculate in a new field in the attribute table to
do this kind of preparation.
For example, if you require a place in a particular climate, first select the climate polygon(s) you are interested in -- you might even export them to a new layer or virtual layer (e.g., "Humid Subtropical"). Then select places on the basis of location, referring to the desired climate polygon(s).
Continue to apply your requirements, each time exporting the layer to a smaller and smaller qualifying set until you're left with a layer that only contains places which satisfy all the requirements.
IN IMPORTANT SETTING TO KEEP IN MIND -- Under the selection setting
remember to determine whether you want the intersecting places or just
those that are entirely enclosed. In other words, if part of a place
is within your desired climate zone, and part isn't, does it qualify or
not?
Make your <qualifying places> layer current and, in the attribute table make any other necessary formula fields. Now you can use either field calculation or join attribute data to create the necessary data for your preferences.
Example: Making a variable for "how far off from a prefered
amount of rainfall"
Let's say you like 35 inches of rain -- more would begin to be too
wet, less too dry. You have a column called "inches" in the rainfall
layer. With calculate, refer to the "inches" data to your places
layer and then apply this formula: ABS(inches-35). The bigger
the absolute value, the worse the rainfall.
(((P1-AvgP1)/AvgP1)*W1)+(((P2-AvgP2)/AvgP2)*W2)-(((N1-AvgN1)/AvgN1)*WN1) ... where
The [Per Capita Income] and the [P Below Poverty]
are the two variables (the actual values are different for each case, so
refer to the variable name), and the other values are fixed (they are the
same for every case, so type in the value itself). Income is added (no
initial + sign needed), and Percent Below Poverty is subtracted -- because
the higher the worse -- it's a bad thing. When you add the other
preferences in the same way (remember, at least three), you will
have your index of favorite places -- the bigger the number, the better
the place. Sort by the place column and you'll see the best (or worst --
among qualifying places).
Note: One weakness of this method is that some values vary from the mean more than others. For example, percent possible sunshine may average 50 but run anywhere from 5 to 95; whereas the male-female ratio may average 100 (100 men per 100 women) and may vary from 95 to 105. If you use these two with the formula above, sunshine will be automatically "weighted" much more highly than the M:F ratio. You should be using "standardized" values instead. Interested in addressing these issues? See me about an independent study.
© 1997-2004 Erick Howenstine
Here's an excellent
example from 2003.