Lesson 4 Lab

Lesson 4 Lab

Color and Choropleth Mapping in Series

In Lab 4, we will explore different ways of choosing data classification and color schemes for choropleth maps. As a cartographer, you will often have to choose between several of these options - many of which may seem at first glance to be equally appropriate. In Lab 3, we used data from the American Community Survey, provided by the US Census - a commonly-used source of data for statistical maps. In this lab, we use the same data source but focus on a specific variable frequently in focus during public policy debates: health insurance.

The first part of Lab 4 will focus on data classification. There are many ways to classify statistical data on maps, and it is important that you understand them, and be able to defend your choice of classification scheme to others. As we will be not only be classifying data but also adding that data to maps, this lab will also focus on the use of color on maps. Finally, as suggested in the lesson content, we will explore ways of making comparable maps - in this lab, we will be making three pairs of maps. 

This lab, which you will submit at the end of Lesson 4, will be reviewed/critiqued by one of your classmates in Lesson 5. 

Lab Objectives

• Create three pairs of county-level choropleth maps describing health insurance in New England.
• Utilize shared or similar legends to help readers understand the relationships between pairs of maps.
• Use information about data distributions and health insurance rates in New England and the US overall to plan shared data classification breaks.
• Understand the impact of different color schemes and classification methods; be able to reflect upon and write about these decisions.

Overall Lab Requirements

For Lab 4, you will create three pairs of maps, each pair as its own full-page map layout. In total, you will have three separate pages. Two maps will appear on each page. You will also write a short reflection statement about each pair of maps.

• For each pair, use the same map positioning and scale within each frame; one scale bar for both maps.
• Prepare balanced page layouts with all elements suitably sized and balanced negative space—no pinched elements or visual collisions.
• Attend to text hierarchy: overall title, subtitles, legend title(s), legend class labels, scale, data source, and name. Use thoughtful and efficient wording when labeling map elements.

Map Requirements

Map Pair One: Use a Sequential Color Scheme

• Choose two related variables to map from the provided American Community Survey (ACS) data.
  • Do not just choose two age groups (e.g., 18-under; 19-25 years).
• Select class breaks manually: Create dot plots in Microsoft Excel and draw appropriate breaks using your eye to judge the data; enter these as manual breaks in ArcGIS Pro.
• Use a sequential color scheme and a single shared legend for both maps.
• Include a short write-up (100+ words) which includes a screenshot of your dot plot with lines drawn to demonstrate the breaks you chose, as well as a short description of how you selected these breaks. Also, include a screenshot of the symbology pane for both maps.

Map Pair Two: Use a Diverging Color Scheme

• Re-create your maps from map pair #1 using a diverging color scheme.
• Choose a critical break or class using external information – you can either use a value that is directly derived from your chosen data set (e.g., the mean of the data) or any logical dividing point that is calculated from an external source (e.g., the U.S. national average); adjust other class breaks accordingly.
• Use a single well-designed shared legend for both maps.
• Include a short write-up (100+ words) describing the critical break or class you chose and why. You may also discuss why you selected this particular color scheme. 

Map Pair Three: Unclassed vs. Classed Maps (Choose your own appropriate color scheme)

• Choose one of the maps from map pairs #1 and #2 and create two more maps of this data—unlike in the previous layouts you made, these two maps will show the same data/topic.
• One of the maps should be an unclassed map; one should be classed. 
• For the classed map, choose a classification method available in ArcGIS Pro—do not manually adjust the class breaks created, but ensure that this method is appropriate for the data you are mapping.
• Include a well-designed legend for each map.
• Include a short write-up (100+ words) that describes why you chose the classification method you did, and how you think its effectiveness compares to that of the unclassed map.

Lab Instructions

1. Download the Lab 4 zipped file (43.2 MB). It contains:
   • a project (.aprx) file to be opened in ArcGIS Pro;
   • a database that includes the spatial boundary and health insurance data needed to start this lab;
   • a spreadsheet containing New England health insurance data.
     • Data source: US Census Bureau - TIGER boundary files and American Community Survey (ACS) S2701 (Health Insurance Coverage Status) 5-year estimates for 2016.
     • For the purposes of this lab, New England is defined as the following states: Massachusetts, Connecticut, Rhode Island, Vermont, New Hampshire, and Maine.
2. Extract the zipped folder, and double-click the blue (.aprx) file to open ArcGIS Pro.
   • In addition to the ArcGIS Pro file, you will also be using the ACS_2016_NewEngland_HealthInsurance.xlsx file to explore New England health insurance data.
   • Note that you will not need to import any data into ArcGIS Pro - all data is included and ready to map. The Excel file is only for visually exploring the data in order to select class breaks for your maps.

Grading Criteria

A rubric is posted for your review.

Ready to Begin?

More instructions are available in the Lesson 4 Lab Visual Guide.