Axis
31 posts
The Financial Times published the following chart that shows the rollout of vaccines in the U.K. (I can't find the online link to the article. The article is titled "AstraZeneca and Oxford face setbacks and success as battle enters next phase", May 29/30 2021.) This chart form is known as a "streamgraph", and it is a stacked area chart in disguise. The same trick can be applied to a column...
The following chart was forwarded to me recently: It's a good illustration of why the "start at zero" rule exists for column charts. The poor Indian lady looks like a midget in this women's club. Is the average Indian woman really half as tall as the average South African woman? (Surely not!) The problem is only superficially fixed by starting the vertical axis at zero. Doing so highlights the fact...
Art sent me the following Economist chart, noting how hard it is to understand. I took a look, and agreed. It's an example of a visual representation that takes more time to comprehend than the underlying data. The chart presents responses to 3 questions on a survey. For each question, the choices are Approve, Disapprove, and "Neither" (just picking a word since I haven't seen the actual survey question). The...
Long-time reader Scott S. asked me about this Washington Post chart that shows the disappearance of pediatric flu deaths in the U.S. this season: The dataset behind this chart is highly favorable to the designer, because the signal in the data is so strong. This is a good chart. The key point is shown clearly right at the top, with an informative title. Gridlines are very restrained. I'd draw attention...
I struggled to decide on which blog to put this post. The reality is it bridges the graphical and analytical sides of me. But I ultimately placed it on the dataviz blog because that's where today's story starts. Data visualization has few set-in-stone rules. If pressed for one, I'd likely cite the "start-at-zero" rule, which has featured regularly on Junk Charts (here, here, and here, for example). This rule only...
In reviewing a new small-scale study of the Moderna vaccine, I found this chart: This style of charts is quite common in scientific papers. And they are horrible. It irks me to think that some authors are forced to adopt such styles. The study's main goal is to compare two half doses to two full doses of the Moderna vaccine. (To understand the science, read the post on my book...
It's always very interesting as a writer to look back at a year's of posts and find out which ones were most popular with my readers. Here are the top posts on Junk Charts from 2020: How to read this chart about coronavirus risk This post about a New York Times scatter plot dates from February, a time when many Americans were debating whether Covid-19 was just the flu. Proportions...
This chart appeared in a Charles Schwab magazine in Summer, 2019. This bubble chart does not print any data labels. The bubbles take our attention but the designer realizes that the actual values of the volatility are not intuitive numbers. The same is true of any standard deviation numbers. If you're told SD of a data series is 3, it doesn't tell you much by itself. I first transformed this...
This chart is giving me feelings: I first saw it on TV and then a reader submitted it. Let's apply a Trifecta Checkup to the chart. Starting at the Q corner, I can say the question it's addressing is clear and relevant. It's the relationship between Trump and McConnell's re-election. The designer's intended message comes through strongly - the chart offers evidence that McConnell owes his re-election to Trump. Visually,...
The Washington Post reported a surge in donations to the Democrats after the death of Justice Ruth Ginsberg (link). A secondary effect, perhaps unexpected, was that donors decided to spread the money around; the proportion of donors who gave to six or more candidates jumped to 65%, where normally it is at 5%. The text tells us what to look for, and the axis labels are commendably restrained. The color...