"Color is a power which directly influences the soul." -Wassily Kandinsky
It’s August, so it seems appropriate to talk about heat maps. I’ve blogged about this simple yet powerful chart type before. It takes advantage of the power of color like no other chart I know. Heat maps use variations in color to show differences among categories (e.g. people living in different zip codes) or differences across a scale (e.g. people with different income levels). In a lot of cases, it’s simply a table with color added to the cells.
The enormous potential of a heat map is clear in Philip Bump’s recent heat map in The Washington Post, which took its inspiration from Thomas Wood’s similar chart. As Bump notes, this chart is “elegantly simple.” The rows are states, grouped by region. The columns are presidential election years. And shades of red and blue indicate the parties of candidates who won in each state, with darker shades indicating wider margins. Here’s part of the chart:
Source: The Washington Post, August 24, 2021
By carefully grouping the states into regions and subregions, the chart reveals interesting patterns: shifts from blue to red (and vice versa) as well as shifts from greater to lesser margins (and vice versa).
Think about how you can show change over time in the problems you are addressing or the services you are offering using color and strategic groupings. Here are some possible applications for organizations like yours:
Show shifts in service use over time among two (or more) groups such as adults represented by one color and children represented by another. Each row might be a zip code area and rows could be grouped by city.
Show changes in pollution over time produced by two (or more) sources such as vehicles represented by one color and factories by another. Each row might be a country and rows could be grouped by continent.
Show variation in client make up over time among two (or more) groups such as higher income groups represented by one color and lower income groups by another. Each row might be a program site and rows could be grouped by neighborhood.
You can create heat maps in many data viz programs. Here is how to create them in Excel and in Tableau.
Let’s talk about YOUR data!
Got the feeling that you and your colleagues would use your data more effectively if you could see it better? Data Viz for Nonprofits (DVN) can help you get the ball rolling with an interactive data dashboard and beautiful charts, maps, and graphs for your next presentation, report, proposal, or webpage. Through a short-term consultation, we can help you to clarify the questions you want to answer and goals you want to track. DVN then visualizes your data to address those questions and track those goals.
