Assignment #8: Data Classification and Choropleth mapping


  1. Download this table of data on Douglas/Sarpy county by census tract. One of the data columns will be assigned to you. Classify this data into 5 categories using the equal interval (equal steps), quantile, natural breaks, and standard deviation approaches.
  2. Determine the number of observations in each category using the Excel FREQUENCY function. This video explains how this works.
  3. Create a legend for each classification method, as depicted below, that includes the number of observations in each category. Use this Illustrator template file. Save as "legend.png" and link from your webpage.
  4. Link your Excel file with the four tabs for each classification from your website. The code for linking both files should look something like this:
    <li>Week 6: <a href="classes/classifications.png">Classifications</a> || <a href="classes/table.xlsx"> Table </a> <br>
  5. GRAD STUDENTS: Also range-grade the data between 0-100% ink. Don't incorporate the perceptual adjustment. Create the "legend.png" file with 10 sample values that are equally spaced between the minimum and maximum values.

6. Convert one of your legends (not the quantile) to a horizontal histogram using Illustrator's graphing function || Youtube instructions


Ungroup and delete the extraneous graph elements. Shade with ColorBrewer. Add numbers to each bar.