- Chapter 9 in Alberto Cairo, The Truthful Art1
- Chapter 12 in Claus Wilke, Fundamentals of Data Visualization2
- Kieran Healy, “Two y-axes”
- Two Alternatives to Using a Second Y-Axis & Illusion of success & Dissecting two axes
- Dual-Scaled Axes in Graphs: Are They Ever the Best Solution?3
Questions to reflect on
- How can you correctly and honestly communicate relationships between variables? How can you communicate the uncertainty in those relationships?
- What are the dangers of visualizing two variables?
- When is it appropriate to use two y-axes?
The slides for today’s lesson are available online as an HTML file. Use the buttons below to open the slides either as an interactive website or as a static PDF (for printing or storing for later). You can also click in the slides below and navigate through them with your left and right arrow keys.
Fun fact: If you type ? (or shift + /) while going through the slides, you can see a list of special slide-specific commands.
Videos for each section of the lecture are available at this YouTube playlist.
You can also watch the playlist (and skip around to different sections) here:
Alberto Cairo, The Truthful Art: Data, Charts, and Maps for Communication (Berkeley, California: New Riders, 2016).↩︎
Stephen Few, “Dual-Scaled Axes in Graphs: Are They Ever the Best Solution?” Visual Business Intelligence Newsletter, March 2008, http://www.perceptualedge.com/articles/visual_business_intelligence/dual-scaled_axes.pdf.↩︎