Community Guide: Mapping Census Data for Your Town
Frank D. Beck, Illinois State University and Julie Pelton, The Pennsylvania State University

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Rationale

Communities play an important role in our lives. Some would say that their role in shaping us is second in importance only to the family. The laces where we have lived serve as the nexus of a number of social forces affecting who we have become (for example, the economy, environment, culture, education, and so on). It is also true that all places are not the same; they are structured differently, and these structures have changed over time. You are now going to have the chance to look at how socioeconomic characteristics are distributed within your town and to write why you think they are distributed that way. The intent is for you to see your town differently than you have ever seen it before and for you to come up with reasons for why the statistics are the way they are and why the maps look the way they do.

For this assignment, you will need to know how to use the Web. If you have never browsed before, let your instructor know. You will also need to pick a town in the United States on which you want to focus. You will need to know something about this place – where it is, what its geography looks like, what country it is in, and where the town is in the county (an atlas will help you with the last two points). It is best, therefore, if you focus on the town in which you grew up in or the place that you now call home. Using the instructions from class and those on the “Specific Instructions” page below for working with the Ciesin/Sedac Web page (http://plue.sedac.ciesin.org/plue/ddviewer/), you will map the distribution of various socioeconomic characteristics of your town or city.

Instructions

1. You will map the distribution of the following three Census variables for your county and town. I have decided what three of the variables should be:

• Percent of the population below the poverty line (the variable name is pctpoor )

• Percent of the housing units built before 1940 (the variable name is pctblt40 )

• Median value for houses (the variable name is medhval )

These are found in various places on the list of variables. The variables are not listed in alphabetical order.

2. For each of these, you need to get the detailed statistics for that variable for your county. Find the minimum and maximum values for each of the variables. Include these values on your worksheet.

3. You need to pick two more variables you want to map and write about. You should stick with the variables that are already in percent (race/ethnicity, education, percentage of persons below 50 percent of poverty) or average/median form (income, housing values, gross rent, and so on). A variable that is a count of persons in a certain category will vary more by the number of residents in the space than by socioeconomic differences across space. Obtain the minimum and maximum for these variables, as well.

4. You will print out and turn in all five maps. Indicate on them where your neighborhood or town is, and number or title each map to match the label that you gave them on the worksheet. If you view the maps in one place and need to save them and print them elsewhere, click the right mouse button while the pointer is on the map itself.

5. Write legible descriptions for the maps on the worksheets, and staple them together with the maps. Put the maps in the order that you discuss them in the description. In the description, you should answer the following questions:

• Why is the variable distributed this way for your town?

• Why is it distributed this way for towns surrounding your town?

• If there are any drastic differences within your county, you should mention these. Of course, the fact that there are no major differences within your county might also be noteworthy.

• Lastly, does this tell you anything about your town that you did not know before, or does it reinforce what you already knew?

NOTE

The descriptions should be more than simplistic: a 0-2 percent poverty rate is not just because your town is middle class; you should describe why you think your town is middle class and why it is able to keep poverty low (refer to the sample worksheet).

Grading

Your grade is primarily based on how well you describe each of the maps. You should assume that your instructor knows very little about your town or neighborhood, so you should explain in detail why the variable in question is distributed the way it is. This description includes listing the minimum and maximum values for the county in which your neighborhood is located.

Specific Instructions for How to Use the Ciesin DDViewer Web Page

To Begin:

In your browser, go to http://plus.sdac.ciesin.org/plue/ddviewer/.

Click Launch Non-Java Edition v.2.

Click the state of the town or neighborhood that you want to examine.

Scroll to the country of the town or neighborhood that you want to examine and click it, then click Submit.

You have to do the following on the next screen:

Select the summary geographic level:

• For those from more rural counties and for those from cities (50-100,000 persons), this task can be done at the tract or block-group level. Mapping at the county subdivision level will show you differences by township.

• For those from the suburbs, tract, block-group, or county subdivisions might work; the more populated the county is, the more you will have to rely on tracts or county subdivisions. The more rural the county, the more you will have to rely on block-groups or subdivisions.

• For those form large cities, you will have to do this task at the tract level and use an atlas to help you identify which neighborhood is yours.

Select the variable ranging method. Change this value from quartiles to 4 or 5 (this action splits the range of the variable from lowest to highest score into quartiles or quintiles). If you do not perform this action, your legend will simply indicate Q1-Q4 instead of actual ranges for that variable.

Select variables: They are not listed alphabetically, so you will have to search for the ones I told you to map first. It is up to you what the other two variables are. You can only map one variable at a time.

Ignore the Equation Option and Mapping Variable Option boxes.

You can change some of the select Mapping Patterns if you wish. You might have to experiment with moving the legend around so that you can see the whole map and your town or neighborhood within it. Changing the colors might be necessary if you are printing in black and white. You can experiment as well with the Map Title and Subtitle boxes.

Also ignore the output Format Options boxes.

Once you are all set, click Submit.

Click Map Image to see the map.

It is now up to you to know where your town or neighborhood is within the county and to interpret the different colors on the screen. To do the latter, know which variable you graphed, and start to think about why those data are distributed across space in the manner that they are.

To change previous settings (such as geographic level, variable name, legend position, and so on), click Back.

You should print each map on an inkjet or laser printer (do not try dot matrix). Your descriptions of each should be written, typed, or copied onto the sheets provided; just make sure that you label the maps so that the instructor knows which map you are talking about.

To discover the space with the least (minimum) or most (maximum) of whatever variable you mapped, click descriptive statistics or attribute data instead of map image.

Definitions You Need to Know for This Assignment:

County subdivision – Cities, towns, villages, townships, and so on within a county

Census tract – A Census-defined space that consists of approximately 4,000 persons

Block-Group – A Census-defined space that consists of approximately 1,000-1,300 persons; there are 3-4 block-groups in a tract.

Mapping_Census_Data_for_Your_Town_Worksheet

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