Geog assignment

Geog 1502: Mapping Our World | 1

Lab 4: Simplification

Overview. This lab asks you to analyze data from the US Census relating to poverty. We will

map these data to better understand how simplification via classification and generalization

changes the meaning of maps. Poverty is the proportion of people who meet the census

definition of poverty. In 2015, for example, this was $12,082 for one person and $ 24,257 for a family of four. Over 43.1 million Americans lived in poverty in 2013. See the Moodle section for

this lab for the link US Census Poverty Information to read about how the Census defines and

measures poverty. You will draw on this information in your deliverable.

Procedure

1. Social Explorer. Return to Social Explorer via the following URL. Recall that if you are off campus, you may need to sign in using your x.500 account to gain access. Also note that you

must allow pop-ups for the site in your browser.

► http://www.lib.umn.edu/get/14592

2. Explore Data. We will use the mapping interface. Click on the Maps tab at the top of the page. Click the link for Start Now under the U.S. Demography section.

We are going to explore the number of adults (age 18-64) reported to be living in poverty in

1999. Under Change Data, select Census 2000. Under the category Poverty and then scroll

down to the subheading Poverty Status in 1999 for Population Age 18 to 64, select Living

in Poverty (see Figure 1 below). Show data by Automatic.

Figure 1. Poverty Menu Selection

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Now you are going to explore differences in classification systems by creating three separate

maps. Using the same poverty data for adults that you selected above, click on the Cut-

Points button in the drop down menu on the upper right hand column (per the figure below,

click on the arrow at the upper right-hand corner of the map and choose “Cutpoints” from the

drop down menu). The default screens should look something like Figure 2 below.

Figure 2: Cutpoints

Experiment with the different classification schemes that we read about and discussed in class:

Quantile, Equal Interval, and Jenks Natural Breaks (found under the Classification Method

drop down menu shown in Figure 2). Examine these maps by zooming into specific regions to

see how the maps differ due to the classification scheme. Look at the differences and similarities

in these maps, and keep them in mind when you complete the lab deliverable. Figure 3 below

shows approximately what your maps could look like.

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3. Map Data. Choose a classification scheme that you feel is best suited to your data – one that you feel most clearly illustrates the spatial distribution of poverty in the US. Using the

buttons for Colors and Number of Classes (see Figure 2 above), choose a color scheme you

feel is suited to your data and select the number of classes you feel are appropriate. Feel free

to experiment a bit here, making sure you get a sense of how changing hue and value affects

what the map tells you, as well as the apparent impacts of varying the number of classes.

Make sure your map has a legend by taking a screen shot of the legend from the drop down

menu in the top right corner. Also add a Title, Data Source, and any other applicable

information. Refer to the instructions for Lab 1 and the Maps in Assignment document for

more detailed information on how to do this.

Note: You are encouraged to draw upon course readings in your answers.  You must use quotation marks for any direct quotes, citing the author (for general ideas)

and page number (for specific statements), such as “(Manson: 12).”  Full citations are not required for course readings, whether they are the PDFs of chapters

or articles, or the website readings.  You must use a full citation for any source not part of the course readings.  The title of webpage and link are sufficient for an online source not part of course

readings.  Failure to cite a source – whether a course reading or an external source – constitutes

plagiarism.

Finishing Your Lab

There are four steps to finishing this lab:

1. Answer the questions posed in the separate lab deliverable document, which is available in MS Word format via the Lab 4: Deliverable link on Moodle.

2. Complete this deliverable document in MS Word. 3. Save or print the deliverable as a PDF file with the title, “Lastname_lab4”. Jill Smith, for

example, would title her file in Word as Smith_lab4.pdf.

4. Submit your document to Moodle via the Lab 4: Submission link. Your lab will be submitted via Moodle’s TurnItIn function.

Figure 3. From left to right: Quantile, Equal Interval, and Jenks Natural Breaks

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