Variance

48 posts
The epidemic of simple comparisons

Another day, another Twitter user sent a sloppy chart featured on TV news. This CNN graphic comes from Hugo K. by way of Kevin T. And it's another opportunity to apply the self-sufficiency test. Like before, I removed the data printed on the graphic. In reading this chart, we like to know the number of U.S. reported cases of coronavirus relative to China, and Italy relative to the U.S. So,...

0 0
More visuals of the economic crisis

As we move into the next phase of the dataviz bonanza arising from the coronavirus pandemic, we will see a shift from simple descriptive graphics of infections and deaths to bivariate explanatory graphics claiming (usually spurious) correlations. The FT is leading the way with this effort, and I hope all those who follow will make a note of several wise decisions they made. They source their data. Most of the...

0 0
All these charts lament the high prices charged by U.S. hospitals

A former student asked me about this chart from the New York Times that highlights much higher prices of hospital procedures in the U.S. relative to a comparison group of seven countries. The dot plot is clearly thought through. It is not a default chart that pops out of software. Based on its design, we surmise that the designer has the following intentions: The names of the medical procedures are...

0 0
Marketers want millennials to know they’re millennials

When I posted about the lack of a standard definition of "millennials", Dean Eckles tweeted about the arbitrary division of age into generational categories. His view is further reinforced by the following chart, courtesy of PewResearch by way of MarketingCharts.com. Pew asked people what generation they belong to. The amount of people who fail to place themselves in the right category is remarkable. One way to interpret this finding is...

0 0
Who is a millennial? An example of handling uncertainty

I found this fascinating chart from CNBC, which attempts to nail down the definition of a millennial. It turns out everyone defines "millennials" differently. They found 23 different definitions. Some media outlets apply different definitions in different items. I appreciate this effort a lot. The design is thoughtful. In making this chart, the designer added the following guides: The text draws attention to the definition with the shortest range of...

0 0
The rule governing which variable to put on which axis, served a la mode

When making a scatter plot, the two variables should not be placed arbitrarily. There is a rule governing this: the outcome variable should be shown on the vertical axis (also called y-axis), and the explanatory variable on the horizontal (or x-) axis. This chart from the archives of the Economist has this reversed: The title of the accompanying article is "Ice Cream and IQ"... In a Trifecta Checkup (link), it's...

0 0
Pulling the multi-national story out, step by step

Reader Aleksander B. found this Economist chart difficult to understand. Given the chart title, the reader is looking for a story about multinationals producing lower return on equity than local firms. The first item displayed indicates that multinationals out-performed local firms in the technology sector. The pie charts on the right column provide additional information about the share of each sector by the type of firms. Is there a correlation...

0 0
Tennis greats at the top of their game

The following chart of world No. 1 tennis players looks pretty but the payoff of spending time to understand it isn't high enough. The light colors against the tennis net backdrop don't work as intended. The annotation is well done, and it's always neat to tug a legend inside the text. The original is found at Tableau Public (link). The topic of the analysis appears to be the ages at...

0 0
Choosing between individuals and aggregates

Friend/reader Thomas B. alerted me to this paper that describes some of the key chart forms used by cancer researchers. It strikes me that many of the "new" charts plot granular data at the individual level. This heatmap showing gene expressions show one column per patient: This so-called swimmer plot shows one bar per patient: This spider plot shows the progression of individual patients over time. Key events are marked...

0 0
As Dorian confounds meteorologists, we keep our minds clear on hurricane graphics, and discover correlation as our friend

As Hurricane Dorian threatens the southeastern coast of the U.S., forecasters are fretting about the lack of consensus among various predictive models used to predict the storm’s trajectory. The uncertainty of these models, as reflected in graphical displays, has been a controversial issue in the visualization community for some time. Let’s start by reviewing a visual design that has captured meteorologists in recent years, something known as the cone map....

0 0