Poor Label Placement

Image taken from an ESO press release about targeting dim objects near bright ones.

I was going to make just one snarky comment: namely, that one should be cautious where one places text in a contour plot… Or else one ends up with a small, circled “A” that misleadingly suggests the wrong location for an object.

Then I looked at the image and asked myself why the heck the contour lines were there at all (except to add visual confusion). As far as I can tell, they simply represent the same data shown by the pseudocolor image underneath. In other words, we’re being redundant on top of placing text poorly and haphazardly on the image.

Why do people insist on the entire freakin’ rainbow for their pseudocolor images? Is it because they’re trying to use up ink in their printer cartridges at an even rate? Is it because they can’t walk to their nearest public library and pick up an Edward Tufte book that will help set them straight?

Sigh. It’s been a long day. Time to go to another meeting…

Pull My Finger

New York Magazine recently posted “The Science of Gaydar” to its site, which uses the above figure to illustrate one of various physical attributes that are statistically correlated with sexual orientation (straight on the left, gay on the right, by the way). Others include fingerprint density, hair whorl direction, and handedness. With minimal captioning and added text, the magazine’s designers have created a sequence of simple, easy-to-understand images. Admittedly, it’s not exactly rocket science, but clarity and elegance go a long way in my book.

For example, note how the type in the above image guides you toward seeing which digit is longer. Placing the text above and below the dotted line gives you a tiny bit more information than you would otherwise have, and the result is both aesthetically pleasing and impressively lucid. Great work!

FYI, my index finger is indeed longer than my ring finger. Go figure.

Colorbar Confusion

A press release from Purdue University describes the effect of greenhouse gas emissions on “heat stress,” using the diagram above to illustrate the difference in effect between accelerated emissions (top) and decelerated emissions (bottom). A description from the web page:

“This image illustrates heat stress in the 21st century for two greenhouse gas emissions scenarios. The top panel shows the expected intensification of the severity of extreme hot days given accelerating increases in greenhouse gas concentrations. The bottom panel shows the expected decrease in intensification associated with decelerated increases in greenhouse gas concentrations.”

(I apologize for the nearly illegible size… The Purdue website offers up the diagram in the teeny-tiny size above, or print quality, which I assumed would be excessive.)

There are a couple of things I find odd (and counterintuitive and frankly counterproductive) about the diagram…

Firstly, the color spectrum used in this false-color representation of the data feels wrong to me, since it ranges from cool blues through warm oranges and reds and thence to… The beginnings of a cool violet? Particularly since we’re talking about temperature (well, sort of) here, and most people have grown accustomed to weather maps colored by temperature. Stopping at red gives you plenty of color resolution. (And maybe next time, you can choose something other than the garish rainbow colors?)

A more egregious error permeates the diagram, however. Perhaps we can simply call this the “apples and oranges&rduo; issue: two images, side-by-side, offered up for comparison, need to share enough to allow for easy comparison. I last blogged about this in relation to an NCAR visualization of Hurricane Katrina, but the idea is simple enough: don’t ask the viewer to do unnecessary work in interpreting your imagery, because unnecessary work leads to unnecessary risk of miscommunication. In the case of the two images above, the color bars are flipped for no apparent reason, so increasing values get warmer (in hue) on the top and cooler (in hue) on the bottom. Why? Also, the scale of the two color bars changes, running from 3 to 8 on top and from –3 to 0 on the bottom. Why? Why? Why?

(Well, okay, I can acknowledge one drawback in this particular case. Since the two datasets do not overlap, coming up with a single colorbar would be a little tricky; indeed, you’d almost need to insert an intermediate model showing, say, no change in greenhouse admissions, which would presumably result in values in between. But the issue of inverting the colorbar still stands: “red on top bad, red on bottom goooood” simply leads to confusion.)

I find behavior of this sort annoying when watching a scientist presenting data in a talk, but as part of a press release, it just saddens me. My fear is that the folks in the university press offices don’t even try to fix these problems… Perhaps because they don’t care, but perhaps because they don’t even think the data should be easily understood.

Hmmm. Maybe it’s time for a Tufte-like “Graphics 101” for science types? I looked for such a thing just now, but I didn’t find anything. Anyone reading know of such a thing?

Skytruth



The above images come from Skytruth, a non-profit “using remote sensing and digital mapping to educate the public and policymakers about the environmental consequences of human activities.” On the top, you can see Wyoming’ Upper Green River Valley in 1986, and on the bottom, in 2005, after the construction of approximately 700 natural gas wells. The organization’s website offers more details on the particular events in Wyoming (and many, many other places on Earth), but the main point should be clear: data speaks!

I just saw a presentation by Skytruth’s founder, John Amos, at the International Symposium on Digital Earth. Blogging while he spoke… Hope he’s not offended.

Visualizing Science Education

Funny. I just got out of a meeting in which we were discussing public perceptions of science and the role of formal education. Then I see this comic: bored students learning (sans even rudimentary visuals) one of the most exciting results of modern cosmology. And made to feel small to boot!

Oddly enough, the kids’ science class is apparently taught by the brunet half of Hall and Oates, which would have made him no cooler in my generation than he is in this.

A Pup out of Water

A brief thought for the day. How does it make you feel, knowing that the image above represents fully seven percent of the world’s population of Devil’s Hole pupfish?

Interesting how knowledge changes context. A San Francisco Chronicle article from today discusses the fate of the pupfish, and it’s not exactly rosy. Forty-two of the fish remain, and the population doesn’t appear to be on the rise. But above, you see a picture of a few—a few members of a species about to disappear forever. How does knowing that change the image?

Periodic Spirals—and the Third Dimension

I ran across an image similar to the above on page 86 of Philip Ball’s marvelous little The Elements: A Very Short Introduction, part of an impressive series from Oxford University Press. (I highly recommend these wee volumes, which offer a lot of bang for the buck, at least in the limited selection of titles I’ve perused.)

Anyway, the image. It shows the “lemniscate spiral” of a certain William Crookes (not exactly a household name, but an interesting fellow nonetheless). I have previously blogged about the periodic table, but I find this attempt particularly intriguing. Crookes was trying to visualize the relationship between various elements in three dimensions, which is the kind of thing we do without thinking nowadays, but in the late 19th Century… Of course you’d have to try constructing a convoluted contraption to convey your idea!

That’s what I find interesting about the image: a 19th-century scientist would use an image depicting the hypothetical three-dimensional object in physical terms. Because the abstraction of three dimensions could not (easily) be conveyed pictorally without reliance on real-world elements to suggest the construct extending outside the plane of the printed page. Honestly, I have no idea whether Crookes physically constructed his “lemniscate spiral” or not, but I’m guessing not. Which is what makes me think this the image is a way of communicating the idea.

Whereas modern tools allow us to visualize data in three dimensions and, at some level, conceive of things in three dimensions, such virtual luxuries were unavailable to Crookes and his contemporaries. Thus the conceit of the physical object.

Interestingly, I know of no modern three-dimensional visualizations of the periodic table. Perhaps someone can point me to something…? But if they exist, I bet they aren’t depicted as physical objects.

Inscrutible Ice Cube

A press release from the University of Delaware uses the above image as a stand-in for a Flash animation (provided without explanation) elsewhere on their site. The caption (surprise, surprise) is utterly useless: “How does the IceCube telescope work? Click here to launch the animation, courtesy of the University of Wisconsin-Madison.” Um, thanks.

The thing is, it’s actually a nice enough animation. I like the little Eiffel Tower for scale, and the iconography is relatively clear, except for the color of the dots changing along the path… But it could certainly use some added text or something. And ironically, if you browse down the animations page and look at the very next option, you find a nicely-annotated Flash animation that actually clears up most of the confusion of the previous animation. The colors of the dots remain unexplained, but otherwise, it’s rather spiffy! (If you prefer, you can take a look at the annotated Flash in Swedish, too.)

So what gives? I hope it wasn’t a conscious decision to eschew the animation with text and supporting verbiage! “Oooh, it looks so cluttered that way.”) But the alternative explanation is plain sloppiness. Hmmm.

Nada y Nada y Nada

Today’s image comes to us from a University of Delaware press release about spintronics; you can also take a look at an associated animation that shows something similarly incomprehensible.

So, first off, you should know that “spintronics” refers to a flavor of electronics that relies on an electron’s spin (as well as its charge) to communicate information. It holds great promise for computation, blah blah blah, and indeed, the advances reported in the aforementioned press release sound significant. But the image…

For those who have studied quantum mechanics, the idea of spin being represented by an arrow will be familiar, but certainly the word “spin” does not connote such a mental image, and incorporating the 3-D arrow icon into the visuals (sans explanation) isn’t exactly a compelling starting point. Then, what exactly is going on, with an electron apparently splitting in two before one (half?) tumbles down a silicon ramp toward… What exactly? The whole sequence of images really, truly communicates nothing. Nada. Nada y nada y nada. Makes me feel like a nihilist.

Also, is it trying to look patriotic, with red electrons, blue silicon, and white “Al,” “CoFe,” and “NiFe” (which, taken together, look more like misspellings than chemical formulae)? The research group did get funding from the U.S. Office of Naval Research. Which also makes me feel like a nihilist.

It’s kewl that a researcher can learn to use freeware to create graphics, but that doesn’t mean the fruits of his efforts are ready for public consumption.

Have a great weekend! I myself am off to New York for a few days.

Side-by-Side

I know I already posted one hurricane-related entry this week, but I have another. This one is related to a press release from the National Center for Atmospheric Research (NCAR) about a new technique “that provides a detailed 3-D view of an approaching hurricane every six minutes.” I was curious what a 3-D view of an approaching hurricane might look like, so I followed the links, and…

I got the above. Hmmm.

To be fair, the page makes no claim for the above to be any kind of 3-D view, but it does supposedly offer a “side-by-side” comparison of radar data (on the left) and “NCAR’s ARW experimental forecast” (on the right). An animation shows the evolution of the hurricane, and as the caption duly notes, “The radar vantage point is stationary, on the Gulf Coast, while the ARW viewpoint follows the hurricane itself.” And therein lies my cavil (I’m trying to find synonyms for “gripe”).

The presentation of the images should facilitate side-by-side comparison; instead, the camparison seems hampered by the graphical choices. The change in background color strikes me as mildly annoying, but the field of view of the two images is also slightly different, and the manner in which the left-hand image obscures the state lines makes comparison even more difficult. It’s rather hard to tell how well the model replicates the observed behavior of the hurricane.

The animation only exacerbates the problems because the simulation follows the eye of the storm whereas the Doppler radar remains stationary (as noted in the caption). C’mon, folks, this is data! You can plot it however you want! Why not present it in a way that allows us to get a real feel for how well the computer model matches reality?

How to do it right, in brief: make the background of the two (observed data and computed data) as similar as possible, in terms of scale and markings (e.g., state and county lines), then plot the same quantities using the same color bar (which, as far as I can tell, is what they did in the above example). Would that be so hard?