SciBlogs

Beach Mouse Pelt Map Mike Dickison Feb 06

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UC San Diego biologist Hopi Hoekstra and her co-authors found that differences between the light-colored beach mice of Florida and their darker cousins can be traced to a mutation in just one gene—at least, it can for the beach mice in Western Florida. Eastern beach mice seem to have evolved their colour some other way. She produced this very nice graphic mapping coat colour and the frequency of light and dark alleles. Her colleague Bill Lynn drew the mouse pelts in Photoshop.

Doesn’t this lay out their argument well? You can read the story they’re telling right off the graphic, even without the surrounding text. I couldn’t resist making a few changes, of course, because I’m fussy:

  1. Fading back the thick black coastline and the black pointers, so the data stood out better
  2. Choosing colours for the mouse ranges that were a bit more similar
  3. Making the color of the pointers match the colour of the ranges (this is pretty subtle, I admit)
  4. Changing the circle fills from black to a more-intuitive dark brown—I used the eyedropper to pick the shade of brown from the darkest mouse
  5. Extending the coastline and range into adjacent states, and labelling the states, because not everybody in the world instantly recognises the shape of Florida
  6. Making the state borders a little different from the coastline; artificial divisions shouldn’t be as prominent as natural ones
  7. And, in a bit of typographic pickiness, raising the baseline of each “=” by half a point (because it needs to match the upper-case letters and numerals) and putting a thin space on either side (a thin space is one you have to delve into the special characters to find—it’s really only used for fussiness like this)

 

I notice it all looks very Edward Tufte now, with his patented Tufte beige, but that wasn’t the intention. The earth-toned color palette comes ultimately from the mice themselves.

If I were to do a serious redesign, my first suggestion would be to move the Oldfield mouse up into Georgia, so that it’s physically separated from the beach mice, and obviously situated inland while they’re in the ocean. Adding a key or a label to explain the two allele colors would be nice, and would almost remove the need for an explanatory caption. But I think the graphic tells the story pretty well as is.

References

There’s a nice popular article on the findings, and the original paper is:
Hopi E. Hoekstra, Rachel J. Hirschmann, Richard A. Bundey, Paul A. Insel, Janet P. Crossland. 2006. A Single Amino Acid Mutation Contributes to Adaptive Beach Mouse Color Pattern. Science, 313(5783): 101–104. 7 July 2006, DOI: 10.1126/science.1126121. (PDF)

A Tufte Library Mike Dickison Feb 01

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To me, the most important books on presenting data graphics are by Edward Tufte. People who create charts as part of their job should keep one or more of them close by, and regularly reread them.

vdqiThe Visual Display of Quantitative Information, 2nd ed.
Edward R. Tufte
Graphics Press, 2001 (orig. 1983) • ISBN: 0961392142

This is the most essential Tufte book, published 30 years ago but so far ahead of its time it looks absolutely contemporary. (Compare it with some of the other data graphics books from the mid-1980s and you’ll see). Tufte here introduces his recurring themes: maximizing the data–ink ratio, stripping away unnecessary furniture and “chartjunk”, showing all the data, and greying out what’s less important. There’s elegant discussions of how readers perceive changes in area, why we shouldn’t think of data as boring stuff that needs livening up, why pie charts suck, and when tables are better than graphs. Some of my favorite examples from here are Minard’s famous chart of the retreat from Moscow, the step-by-step erasure of needless ink from a bar chart, and one of his own early graphs as an example of poor design. And the whole book is beautifully typeset and produced, with restrained use of colour and plenty of white space.

eiEnvisioning Information
Edward R. Tufte
Graphics Press, 1990 • 0961392118

Similar in subject and tone to the first book, though there’s more discussion of mapmaking. The most important concept discussed here is “small multiples”, the fruitful idea that six small graphs instead of one large one can add a new layer of information and reveal large patterns in the data. I’ve personally found this the most enlightening technique to share with newcomers to data graphics, and it’s often the best way to break out of the prison of an unsatisfactory design solution. Tufte also discusses how to use colour effectively and with restraint, and how to successively reveal a process in a linked sequence of diagrams (such as dance notation or calligraphy). I particularly liked his coverage of tabular data, from train and bus timetables to the Vietnam War Memorial. Another fine book.

veVisual Explanations
Edward R. Tufte
Graphics Press, 1997 • 0961392126

This wanders further out of strict chart-and-graph territory to cover depictions of processes, exemplified by the diagramming of magic tricks; if we understand how misdirection works, we can turn it around to draw the reader’s attention to what really matters. There are nice examples of the practical consequences of information graphics, discussing their role in the Challenger disaster and in John Snow’s investigation of the London cholera epidemic. The most valuable concept to me was the notion of the smallest effective difference, with a useful discussion of just how little emphasis is needed to make a point clear in a graphic, and the power of using gray shades and faint lines. (There’s a fun genealogy of rock ’n’ roll too, illustrating parallelism as a graphical tool.) Lovely, but a less immediately practical book than the preceding two.


I’ll be looking at Tufte’s most recent book, Beautiful Evidence, in a later post, as I’ve more to say about that one.

Welcome to Pictures of Numbers Mike Dickison Feb 01

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I’m very pleased to have the opportunity to write about scientific data presentation here at New Zealand Sciblogs—I hope these weekly posts will be as useful for you as your comments and feedback will be for me.

What is Pictures of Numbers?

I’m interested in the practicalities of visually communicating scientific data. Years of academic training favours people who are good with words and numbers, until verbal and math skills become the default means of solving problems. But pictures, and visual thinking in general, can be powerful tools both for doing science and, especially, for communicating it. There used to be whole professions of artists, designers, and publishers who worked alongside researchers translating numbers into pictures, but scientists are increasingly having to do this (along with everything else) themselves. To help with this I have a website, also called Pictures of Numbers, and I’m working on a book which will be a practical, useful guide for busy researchers, covering things they can do right now to make their data more understandable. This blog, and the comments you make, will help determine what eventually ends up in the book.

What will this blog cover?

Most books and sites on this subject tend to be either too abstract and theoretical, or too specialised and technical. I’ll be posting reviews of the most useful books under Reading. To show what doesn’t work, and how to improve it, there will be Makeovers of published graphics; feel free to send me examples, both good and bad, and I’ll have a crack at making them better. I’ll also post general design Tips as well as some more detailed step-by-step How To guides for particular techniques, like editing a graph in Illustrator or choosing the right image resolution. Email me any questions or topics you’d like to see covered and I’ll try to fit them in.

Who am I anyway, and why should you listen to me?

I got interested in visual communication when I started out in exhibition development at the National Museum (now Te Papa), and eventually ended up teaching design and typography at polytech. But I missed working with scientists, so went back to school and did a PhD in the evolution of giant flightless birds at Duke University, in North Carolina. To help pay the rent as a grad student I ran workshops in IT and design; when I got back to New Zealand worked as an information designer, and taught in the Learning Skills Centre at the University of Canterbury. Now I freelance as Adzebill Design. Having a background in both science and graphic design is fairly unusual, I find, and it certainly helps when I’m trying to figure out what story the data is trying to tell.

Enjoy Pictures of Numbers!

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