Making information beautifuland clear

Information is presented too often in ways that bore the reader, or put him off, or simply baffle him. JuLianChampkin looks at four examples that do better things with data

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Usually this section tries to help the aspir-ing student to use one tool or another in thegreat armoury of techniques that are availableto statisticians. This month's Toolkit is slightlydifferent: rather than to teach, it is meant toinspire.

When all the statistics of a project have beendone, the results have to be communicated;increasingly, they have to be communicated to

non-specialists or to the general public. Data canbe presented as tables; but to a non-statisticianfew things are as off-putting as a table of figures.

II Giving • Spending • Fighting II Accumulating • Owing Losing II Earning

"estimated

" Vi> defence budget

$147 To help develcplnqnatlons combat climatechange

$780 OPEC revenue

$206 Big tobaccosettlement

~lraq Warpredictedcosl2003

$31OilspiUcleanup

, Medlcar. & Medlcaiot per year$239 BP revenue

$31Oil spill $13fine" profit

, $352 lIiegaldrugs profits=~~

Global pharmaceutical market

$114Bonuses

$31Profits Erectile dysfunction

Anti-depressants Gifts to doctors

The Billion-Dollar-o-Gram, 2009 figures. Sources: NYTimes, The Guardian, BBe, CNNand other media reports. Note: some slight visual cheating to make things fit.

•(EVIDENCE)

(STRONG)

(PROMISING)

(CONFLICTING)

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(SLIGHT)carnitine

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lipoic acidomega9 vitamin Equercetindandelion flaxseed

oil papain

magnesiumbitter

orange trypsinphenyiaiinefenugreek B5

aspartic acid

iignans palmoilmethionine ancreotin

vanadiumacai chasteberry copper(NONE) blackcohosh

~rc;gat;ls'.....:..,;betacarotene

silica

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oil

vitamin Aisoflovones heartqrrythmias

europeanelder

qinkgobllobc diarrhoea rosehip

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ubiquinol wheotgrass

capsaicin

S e oil? Scientific evidence for popular dietary supplements showing tangible health benefits when taken orally by an adult with a healthy diet. Source: English.:: t; ge placebo-controlled double-blind human trials on PubMed.org, US Office of Dietary Supplements, Herbmed.org, European Medicines Agency

significance

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"'Catastrophic threat' of bird flu"

"Swine flu pandemic has bequn"

-2004

-,----,2009

Bird Flu (262)

2IlOO

(€fiJroximate worldwide deaths)

Ii2r Wasps (1000) .••• Autism Vaccinations (0) .••• Mad Cow Disease (204)

_Wifi(O)

2005 2008

Asteroid CoUision (0) .••• Violent Video Games (Unknown) .••• Swine flu (702)

tiile Phones & Iumours (0).... Mittenium Bug (0) .• SARS (174)

- _ tains out of molehills: a timeline of global media scare stories. Source Google News (worldwide deaths at-e of print)

iled technical reports may be necessary; on-" other hand they may not be, and one picture_ orth a thousand words.

"hole books can, have, and should be writtenut visual presentation of data. One of them

Information is Beautiful, by David McCandless.McCandless is not a statistician; he is a

alist. His skill is in communicating things.- diagrams have appeared in the pages of the

In a good graphic, the user readsthe graphic, not the caption

dian newspaper and elsewhere; here we::=lent four of them. They are not perfect. But

are different, and they are clear, and they_ ey the data in ways that every reader can--' rstand - and that may even stick in the

ow much did the Gulf oil spill affect BP's- ? If Wall Street bankers' bonuses wererwise applied could it eliminate AIDSworld-

- "', and pay for a moderate-sized Olympicon top? And just how much is the war

..Jghanistan costing, compared with what wasicted? Is that a lot or a little compared to,the nation's Medicare? The "Billion-Dollar-o-n shows such things, by area. (A fuller ver-of it, incidentally, shows just how huge thefinancial crisis was - as great as the rest of

chart combined.) Area, rather than length or

height, is what the eye judges size by. All suchcharts of course are only as good as their data,and though sources are given the many caveats,uncert;~i'8~il;Sand problems of definition are ofnecessity skated over.

Trying to show two or more variables onone diagram is notoriously difficult, but it canbe done: the "Snake Oil" bubble-chart shows,simultaneously and clearly, four - the popular-ity of the treatment, its promise, the evidencefor its effectiveness, and what it is supposed totreat. Its message is clear at a glance - thoughthe meaning of the vertical lines could do with

IhO amount a treiabsorbs In Its lIlillme

mob!!Q charge, breathing

plasma screen

targecar Ihe averageWesterner

clarification. (For a classic graphic that showsno fewer than six variables, from army casual-ties and geography to direction of advance andwhat the weather was like, and using only twocolours at that, see Minard's famous diagram ofNapoleon's march on Moscow (Significance, Sep-tember 2008).)

Only a purist would complain about the lackof a vertical axis scale in "Mountains out ofMolehills"; the story it tells is clear. The impor-tance of a story in no way reflects the mediaspace that is given to it. "Tons of Carbon" putssome surprising data before you: does your Face-book page really emit half as much carbon asheating your house? That the numbers are againrepresented by the area, not the height, of theoutlines could be made more plain. And if theton of shrimp really represents 12 tons of car-bon, shouldn't it be the same size as the pig andthe wedding cake?

Which in itself is a plus: errors can be spot-ted. The degree of redundancy - size with thenumber inside - itself forms a cross-check. Asimilar mistake in a plain table of the data justwould not be noticed.

These are sunspots. The mark of a goodgraphic is that the user reads the diagram, notthe caption. Information should be in the pic-ture, not in the words underneath. These passthat test with flying colours.

They are not intended to be copied; rather tohint at what is possible. For many other exam-ples, ingenious, informative and beautiful, seeInformation is Beautiful, by David McCandless,published by Collins at £20.00. The US title isThe Visual Miscellaneum: A Colorful Guide to theWorld's Most Consequential Trivia, published byCollins Design at $26.99.

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burrol cromaUan

small car

you on tee-hourfllght

the averageworld citizen

heating theaverage home

your tcceccckpage the average

Americanone ton of beet(1.100Big Macs)

Tons of carbon emissions per year (unless otherwise stated). Source: New York Times, Environmental ProtectionAgency, IPCC, Energy Information Administration, UNESCO

one ton of chicken(1,400 bargain buckets)

to rear a ChHdto age eve

250~gu.st weddIng

one ton 01shrimp

one Ion 01 pork(50,000 slices 01

bacon) one ton 01 salmon

morch2D11 significance