An amazing amount of data is being visualized here. Mousing on the mapwill pick up the specific data for each county. There is a bar up top for discovering the evolution over time. It would be great if there is an animation button so the map can be played out without clicking. An animated gif will also do (similar to the disease map we featured some time ago).
The colors on the first map represent the origin of the top ethnic group in each county. Within each group, the tint of the color further displays the percentage of the population that group accounts for. The subgroups appear to be 0-2%, 2-5%, over 5%. The last subgroup is very wide.
Not so keen on the second map with all those bubbles. They show the number of people from each country by county. The bubble size is proportional to population. Every version of this map looks the same because the population is concentrated in the cities and the interior is sparsely populated, no matter what ethnic group.
Regardless, this is another laudable effort by the crew at theTimes.
Reference: "Immigration Explorer", New York Times, March 10 2009.
The original graph threw us off our sense of scale. It seemed to be saying all these oil companies are roughly the same size but one grew much faster than the others. The red color and the setting off of the data above the title of the chart seemed to announce some important find.
The junkart version on the right reversed everything to our normal sense of scale. It is a version of the bumps chart, one of my favorites.
So we find that Total is the smallest of these oil companies, about half the size of ExxonMobil -- you wouldn't know that from those abysmal bubbles! Adding to the problem is that the growth data is used to sort the companies while the actual production data is hidden in the data labels.
Total is indeed growing faster but BP is not far behind. The fall of ExxonMobil and Royal Dutch Shell is equally intriguing.
Matt H., who authored the previous post, and Charles G. both pointed to a great example of how people like readers here can make a difference. A bad chart got made over!
The Financial Times
published a chart from a JP Morgan report, using ... you guessed it ...
bubbles to illustrate the deep plunge in market capitalization of many
Some readers at the blog were none too happy with the choice of bubble charts. Among other things, the designer made the common mistake of plotting proportional diameters rather than proportional areas. This is clear from looking at JP Morgan's bubble.
This chart exposes the weakness of bubble charts well. Look at the top row of bubbles. Most of them look so similar it is impossible to know, without spending much time studying the circles, which bank was hurt more.
Eventually, a bar chart was produced. Felix Salmon linked to it. I am not sure how the banks were ordered in this chart. It isn't one of the two obvious dimensions, nor is it in alphabetical order.
In fact, neither the bubble nor the bar chart works well for this case. What we need is the Case-Schiller style asset-bubble life cycle chart. In order to interpret these changes in market caps, we need to know how big was the bubble, and then how steep was the consequent decline. Take a look at our discussion of real estate bubble charts here.
Reference: "Bank capitalization chart of the day", Felix Salmon at Portfolio.com and "Bank picture du jour", FT Alphaville, Jan 21 2008.
Message to readers: I have a large backlog of reader suggestions. Please be patient as I slowly get through them. The frequency of posts will remain lower for the time being as I am busy finalizing a draft of a book. More on that in the near future.
Matt H, a reader, sent in the following entry (with minor edits).
I saw a couple of bad charts on money.cnn.com and thought I'd submit them to you.
They're both part of the same
feature on investment bargains caused by the recession.
It seems to me like both charts would have made their points more
eloquently by using a much simpler, more common form, like a bar
In Chart A, cubes are used to display the difference between
treasury bond yields and AAA municipal bond yields at the two-year
horizon and the ten-year horizon. The volume of each cube corresponds
to the yield for the given type of bond in the given period (I think),
which spreads the one dimension being compared (yields) across three
dimensions, making the differences look smaller than they really are. [...] At the two-year horizon, the two yields being compared are 1.16% for
Treasury bonds and 3.01% for AAA municipal bonds. The yield for AAA
municipal bonds in this case is more than 2.5 times larger than the
yield for Treasury bonds, but the difference doesn't look nearly that
big in the chart provided. [...]
Time out. Let me add that the inadvertent reference to an optical illusion concerning foreground and background! The "outline only" cube on the left should have approximately the same volume as the "solid red" cube on the right (3.01% versus 3.30%) and yet the red cube appeared quite a bit larger because our eyes reacted to the solid color more than thin outlines.
In Chart B, [...] Again, the
metric in question is bond yields: ten-year Treasury bond yields
compared to investment-grade corporate bond yields. The 2008 figure
for each is shown alongside the five-year average. This chart uses the
area of a circle to express these yields, spreading the one-dimensional
value across two dimensions. As in Chart A, the result is a chart in
which the difference between values does not appear as large as it
I will also send
a simple bar chart version of each chart -- the bar charts should illustrate the differences in yields more effectively than the charts actually used in this article.
These are his revised charts:
We can do even better to convert the chart on the right to a time-seriesline chart. Instead of the five-year average, it is better to display the gap beween treasury and corporate bonds for each of the five years plus 2008. This should make for a more eye-catching graphic.
Reference: "Investment in the bargain bin", CNN Money.
Right on the heels of the disastrous bubble chart comes another, courtesy of the NYT Magazine. Bubble charts are okay for the conceptual ("this is really big, and that is really tiny"). This chart wants readers to compare the sizes of the bubbles, which highlights the worst part of such graphs.
Poor scaling is the huge issue with bubble charts. They are the prototype of what I call not "self-sufficient" charts. Without printing all the data, the chart is unscaled, and thus useless (see below middle). When all the data is printed (as in the original, below left), it is no better than a data table.
In the above right chart, we simulated the situation of a bar or column chart, i.e. we provide a scale. For this chart, the convenient "tick marks" are at 10, 20, 34, 41. Unfortunately, this scaled version also fails to amuse.
Note further that the data should have been presented in two sections: the party affiliation analysis and the gender analysis. Also, it is customary to place "Independents" between "Republicans" and "Democrats" because they are middle-of-the-road.
A profile chart is an attractive way to show this data. Here, we quickly learn a couple of things obscured in the bubble chart.
On the issue of abortion, Independents are much closer to Democrats than Republicans. Also, there is barely any difference between the genders, the only difference being the strength of support among those who want to legalize.
Reference: "A matter of Choice", New York Times Magazine, Oct 19 2008.
PS. Based on RichmondTom's suggestion, here are the cumulative profile charts.
Frederic M. sent in this chart, together with his commentary.
Bubbles across rows have vastly different numbers but their circles are
of identical size (or vice versa). It borders on the ridiculous that all
bubbles of the US
row have the same size... The question if teenage birth rates and teen sex are
correlated cannot be eye-balled with this kind of display. The fact that you
cannot compare across rows make this an instance of “chart junk”.
White spaces -- always dangerous. Does lack of bubble imply no data or no abortions/sex?
Sorting -- this is what Howard Wainer called "Arizona first" with a twist (United States)
Loss aversion -- would U.S. readers be resentful if countries like Iceland are excluded? A much reduced version comparing U.S. to say Canada, U.K, Japan and Germany may yield more information for the reader.
Sufficiency -- if all the data are printed as in a table, why do we need the bubbles?
Reference: "Let's Talk About Sex ", New York Times, Sep 6 2008.
Guess where I went for vacation (clue in the chart).
This long, narrow country is divided into 15 regions. In the chart below, an uneven parade of 13 bubbles was used to present some sort of economic projections.The capital of the country was singled out as thetop of the table.
The unevenness has a side effect, that the guiding lines are forced to have differing lengths and bewildering turns.Further, because bubbles have no intrinsic scale, the designer must put all the data onto the map as well, thus failing our self-sufficiency test..
The following bar chart version respects the wide, thin space and yet delivers the data more clearly. The top version displays all the data while the bottom one uses a simple axis. The bottom chart is my preference since most readers are probably interested in approximate and relative comparisons, rather than exact projections. (The map would be better off without colors.)
Reference: "Inversiones entre 2008 y 2012 llegaran a US$ 57 mil millones impulsadas por mineria y energia", El Mercurio, Aug 25 2008.