The purpose of this lab is to familiarize you with the geodemographic data available from the U.S. Census and how to navigate the Census web site. It will give you practice in the basics of effective map construction. Most importantly, it will also teach you about an aspect of the California population.
The map on p. 89 is a simple choropleth map, that is, it shows data by county, with each county colored to represent one of four classes of income (basically, highest, high, low, lowest). The maps on p. 72 are more complicated: They are proportional symbol maps. They show the size of the Native American and the Asian/Pacific Islander groups through the size of cubes centered on the counties. The maps on p. 73 are more complex still: These deliver two different types of information simultaneously. The size of the cubes show the size of the Black and Spanish origin populations by county, and the color of the cubes stands for the proportion of the county population in each group.
Now, looking at all five maps, take brief notes on the patterns each conveys. These will help you later on when you write up your interpretation of the map you make. Where is the wealth in California concentrated? Is it urban, suburban, or rural? Which of the four ethnic groups shown on pp. 72 and 73 are the most concentrated in urban counties, as opposed to rural counties? How would you characterize the distributions of each these four groups in California?
You are going to redo one of these five maps to reflect 1990 Census data (data from the 2000 Census, which we are now undergoing, will not be available for another couple of years, so we are stuck with 1990 data as the most current). Whichever distribution you choose to update, you are going to construct a simple choropleth map (like the one on p. 89). Guidelines for its construction will be provided later in this lab. For now, just pick one of the distributions you'd like to use for your update map.
Click the button for "Go to level State--County (*Tracts and Block Groups)," highlight "California" on the menu below. Then, hit "Submit."
On the next page that comes up, click the button for "Select/retrieve all of the areas below. (may be slow)" and hit "Submit." On the page this brings up, you want to make sure that the button for "Choose TABLES to retrieve (population, race breakdowns, etc.)" is highlighted and then hit "Submit" again.
This brings up a really big table. Browse around this table to see the kinds of things you can learn about a county from the Census. Some of it is pretty weird, isn't it? especially towards the bottom.
Now, you need to check off the data you need from this table. Go along and mark:
After doing that, go alllllll the way back up to the top of this table and hit "Submit." This will bring up a table of choices for you to view your data and save them. The easiest one to look at is HTML format, but, if you print it, it's going to take 27 pages of valuable dead trees.
You can also view it as a tab-delimited format file. If you try this, up will come a pretty ugly spreadsheet of data. You can use the "Save As" choice in your browser's "File" menu at this point. Save it wherever you want to (e.g., your A drive floppy) with an easy-to-remember name (e.g., census90) AND be sure to choose "Plain Text (*.txt) under the "Save as type" menu!!! and then hit "Save."
You can widen or narrow some of the columns (so you can see the county names, for example) by moving the cursor between the grey column names ("A," "B," "C," and so on) until it changes shape and then dragging. You may want to rename the fields (with REALLY short names), since "P0120003" doesn't exactly look like it means "American Indian, Eskimo, or Aleut"). P0010001 is P.1 (Persons); P0120001 is P.12 (Hispanic Origin by Race: Not of Hispanic Origin, White) and so on through P0120010 (P.12...Hispanic Origin, Other race); P080A001 is P.80A. (Median household income); and P114A001 is P.114.A. (Per capita income). You get the idea.
By going through all this, you can reformat Excel so that it will print all these data tidily on 2 pages (rather than the 27 that the HTML format requires). If you use our computer lab in LA4207, you must NOT print the HTML format: You MUST use the Excel format.
So, how do you format Excel to pull off a 2 page, easily readable spreadsheet? Delete the two useless columns (A and B) to save room. You do this by highlighting them by clicking the grey boxes at the tops of the columns (which turns the whole columns black) and then click Edit and Delete. Then, after you've deleted them, highlight columns B through N the same way. Move the cursor between any two of the column headings until it changes shape, and then drag any one of the columns into a slightly narrower column width (and, magically, they'll all shrink to the same size).
Next, select the whole spreadsheet by clicking on the small grey box in the upper left corner of the table. The whole file turns black to show it's been selected. Now, pick a small print size (8 point text).
Now, go into Page Setup Margins to set tight margins so the whole thing will fit on a page (0.50" margins on all sides). Also, in Page Setup Page, pick landscape orientation (this gives the page enough room to cover all the columns on one sheet of paper, so you won't have trouble figuring out which data go with which county).
You also need to Save the spreadsheet. Save it as an Excel workbook. Better safe than sorry!
Now, when you do Print Preview, you'll see they all fit on just two pages of dead tree, which you can print with a clean conscience (and, if they don't, try different fonts, such as "Arial narrow" or "Abadi condensed," when all else fails).
By going to the trouble of getting all these data into Excel, you can use its powerful Data Sort capabilities to group your data into classes that are easy for you to see later on when you're trying to design your map. It certainly beats making charts by hand to figure out your categories!
If all this Excel stuff is just too much for you (believe me, it would save you time in the end by investing a little time at the beginning), you can do this lab with the HTML data on the screen, but you'll be doing all sorts of tedious work by hand with possibly unsatisfactory results. Familiarity with Excel is also a real selling point in looking for work after graduation, too.
Ethnic Group
To do this, select one of these groups: Non-Hispanic White, Non-Hispanic Black, Non-Hispanic Native American, Non-Hispanic Asian, or Hispanic of all races. The first four for each county would be classes P0120001 through P0120004 (or the appropriately named group in the HTML 27 pages of dead tree). Hispanic would entail adding, for each county, everything under Hispanic origin. This is a pain by hand, but it's a piece of cake in Excel. You just sum the columns P0120006 through P0120010. This entails creating another column and then writing the formula =sum(h2:l2) in the second row (top data row) and then copying the formula down the column. You can copy the formula down the column, by moving the cursor over the lower right corner of the cell into which you wrote the formula. The cursor changes into a teeny black cross, which you click and then drag it to the bottom of the column. Instant math -- you don't need to type the formula in manually for all the cells in the column.
Now, for each county, multiply your chosen group by 100 and then divide by the total number of persons in the county (column P0010001). This gives you the percentage of the total population who identified themselves as members of those groups. If you do this in Excel, just create a column for percentages and type the formula =x2*100/b2, where x is the name of the column with your group in it, and then copy it down the column -- instant percentages)
Now, eyeball that column of percentages. It is easier to eyeball if you did this in Excel!!! You can highlight the whole spreadsheet (just click on the empty grey box in the upper left), then click on the Data menu up at the top of the spreadsheet and then click on Sort. It'll ask you which column to sort (usually by the name of the column, such as "percentage") and whether you want it from lower to higher (ascending) or higher to lower (descending). Now, instead of being organized alphabetically by county name, the spreadsheet is organized by the percentage of whichever group you picked.
Now, divide the counties into four classes, ideally with roughly equal numbers of counties in each class (modified by any natural break you see in the sorting): highest percentage, relatively high, relatively low, and lowest percentage).
Income
To do this, select either per capita income or median household income. Per capita income is the average income per person. It is very easy to understand and permits further statistical analysis, but some people don't like to use it because it is very much skewed (can you imagine the per capita income of the Census tract Bill Gates lives in?). Median household income is the middle income: Half of the households have incomes above the median and half below. It has the virtues of being less susceptible to skewing and it does reflect the actual buying habits of people, in which decisions are made at the household level, more than at the individual level. It does not allow for much other statistical analysis, though.
So, pick one and then arrange all the 58 counties of California from highest to lowest income. It is easiest on you to do this sorting in Excel, which is why I keep exhorting you to go to the extra trouble of downloading your data in tab-delimited format and converting it into Excel. It's up to you.
Now, group the 58 counties into four classes: poorest, relatively poor, relatively rich, and richest. Ideally, aim for about equal numbers of counties in each class, but you can modify this by any natural breaks you see in the data (sharp breaks from one cluster of counties to the next).
In the back of the Hornbeck atlas, there are two county maps (Appendix F). Your map will probably be more attractive if you use the blank one, so photocopy the blank map for your cartography, while refering to the named county one to keep all those counties straight.
First, construct a legend. This should include the name of your map (exactly what it is you decided to map) and four boxes to show the reader what your colors mean. Make sure that each of your four categories is absolutely mutually exclusive: There should be no question which class a given number fits. If your lowest class is "less than" whatever value, your highest class should be "greater than or equal to" its lowest defining value. Alternatively, if your lowest class is "less than or equal to" whatever, the highest class should read "greater than" its lowest defining value. Sometimes the easiest way to make sure your classes are comprehensive and mutually exclusive is to write something like "20.000% - 39.999%." That said, go back to p. 89 and see if you can find out what's wrong with the legend for the map on income. Also, include your name somewhere on the map.
Second, go on and color in your 58 counties, using the scheme in your legend. Be very careful and very neat, as attractiveness of the map counts in your grade. If you are already familiar with a mapping program or with a graphics package that can handle maps or with a GIS, you may use it (as long as it conforms to the requirements of this lab), but I will not mark you down for a hand-colored map that is neatly done.