Preparing your requirements
 
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 may be acceptable, less than that, plain 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. 

Applying these requirements may involve making a formula in the attribute table, for example, places between 40% and 80% white.  You'll have to make a "percent white" calculation and then perform a selection by attribute (or two).  Carefully use "remove from selection," "reverse selection," "add to selection" and the other tools you learned early on.
  1. To begin your project, on a scratch sheet come up with a long list of things you feel very strongly about -- things which will disqualify a place from your consideration.
  1. Look carefully for highly correlated requirements and highly correlated preferences.  For example,  median value of home and average income are likely to closely related;  so would climate and rainfall.  Choose one of these.  Your criteria should be measuring different things.
  1. You should end up with at least 3 requirements, possibly 4.
  1. Choose a geographical layer for your results. I strongly recommend place; if you have another idea, clear it with me.
  1. For practical purposes, do any of your requirements really limit the number of places?  Try to have at least one that reduces your "qualifying places" substantially.
  1. Consider the technical task of applying your requirements.  Are any very demanding?  If so, do that one last to reduce the chance of crashing.
  1. Operationalize these variables.  Look at the data available to you, and think about what else you have access to.  Remember that you can now link in information from the census bureau 2000 survey, County Business Patterns, etc.  You can also geocode addresses and zip code centroid match them.
  1. Then translate the conceptual to the operational, as I have done here...

 

CONCEPTUAL OPERATIONAL SOURCE LAYER
Among educated people Greater than 50% of adults have some college Census data Place
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 place with low cost of living Cost of Living Index above average (MSA only)* G&ES 391 MSA
Where housing is inexpensive Average value home Census data Place

*Any data available by MSA came from a book which rated MSAs, and that score can be transferred to all places within the 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.

For this week's assignment, fill out the following form carefully:
 

You may download this page, and in composer delete all but the following table.  Type your information into the table.

REQUIREMENTS (3 or 4)

Conceptual -- what is the your requirement, and why?
Operational -- how *exactly* will you measure/determind this?
Where are you going to get the data?
Will the requirement necessitate any calculation/preparation?  Explain.
Order of Application -- first do the easy ones, then the demanding ones
         
         
         
         

If you are confident you may begin to apply your requirements.  Otherwise, read ahead and start working out your preferences.
The requirement portion of your project must be completed in 2 weeks.