Content for week of Monday, June 27, 2022–Friday, July 1, 2022


Questions to reflect on

(Remember, you don’t need to answer all of these—or even any of them! These are just here to help guide your thinking.)

  • 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.

View all slides in new window Download PDF of all slides

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:

  1. Alberto Cairo, The Truthful Art: Data, Charts, and Maps for Communication (Berkeley, California: New Riders, 2016). ↩︎

  2. Claus E. Wilke, Fundamentals of Data Visualization (Sebastopol, California: O’Reilly Media, 2018), ↩︎

  3. Stephen Few, “Dual-Scaled Axes in Graphs: Are They Ever the Best Solution?” Visual Business Intelligence Newsletter, March 2008, ↩︎

  4. Petra Isenberg et al., “A Study on Dual-Scale Data Charts,” IEEE Transactions on Visualization and Computer Graphics 17, no. 12 (2011): 2469–78, doi:10.1109/tvcg.2011.160. ↩︎