Howie’s Helpful Hints

Howie’s Helpful Hints

Don’t show the data1. Show as little data as possible2. Hide what data you do show

Show the data inaccurately3. Ignore the visual metaphor4. Only order matters

Obfuscate the data5. Change scales mid-axis6. Emphasise the trivial7. Jiggle the baseline8. Austria first!9. Label illegibly, incompletely, incorrectly10. Make it 3D!

Adapted from Wainer, H. (1997) Visual Revelations. Mahwah, NJ: Lawrence Erlbaum Associates, Publishers,.

Howie’s Helpful Hints

1. Show as little data as possible

Howie’s Helpful Hints

2. Hide what data you do show

Mortality Risk Ratio (95% CI) derived from Cox's Proportional Hazards model amongst FHILL cohorts by ethnicity and locality

00.20.40.60.8

11.2

Greeks inGreece

Greeks inAustraliaP=0.0001

Anglo-Celts in

AustraliaP=0.056

Swedes inSwedenP=0.0001

Japanesein JapanP=0.0008

FHILL cohorts

Ris

k R

ati

o (

RR

)

LowerUpperRisk Ratio

Source: PhD thesis, Monash University

Howie’s Helpful Hints

Clearer version:

0.10 0.25 0.50 0.75 1.00

Greeks in Australia

Swedes in Sweden

Japanese in Japan

Anglo-Celts in Australia

Greeks in Greece

Relative mortality rate (all causes)

Drawn using S-plus

Howie’s Helpful Hints

What’s the difference?

Rotated by 90o – labels fit & can be read Logarithmic scale – correct for ratio measure Removed grid lines, background, legend Ordered categories by response variable Monochrome emphasises data, not

decoration

Mortality Risk Ratio (95% CI) derived from Cox's Proportional Hazards model amongst FHILL cohorts by ethnicity and locality

00.20.40.60.8

11.2

Greeks inGreece

Greeks inAustraliaP=0.0001

Anglo-Celts in

AustraliaP=0.056

Swedes inSwedenP=0.0001

Japanesein JapanP=0.0008

FHILL cohorts

Ris

k R

ati

o (

RR

)

LowerUpperRisk Ratio Greeks in Australia

Swedes in Sweden

Japanese in Japan

Anglo-Celts in Australia

Greeks in Greece

0.10 0.25 0.50 0.75 1.00Relative mortality rate (all causes)

Howie’s Helpful Hints

3. Ignore the visual metaphor

Source: Tufte E. (2001) The Visual Display of Quantitative Information. 2nd Ed. Cheshire: Graphics Press

8.14

53.0

83.7

0.180.185.27

6.06.03.5factor Lie

Howie’s Helpful Hints

4. Only order matters

Source: Pravda, 24 May 1982.

Source: Los Angeles Times, 5 August 1979.

Howie’s Helpful Hints

5. Change scales mid-axis

0

5

10

15

20

25

30

0 10 20 30 40 50 60 70

Cannabis use (number of occasions)

Cas

es o

f sc

hiz

op

hre

nia

(p

er 1

000)

Source: Andreasson S et al. Cannabis and schizophrenia. A longitudinal study of Swedish conscripts. Lancet. 1987 Dec 26;2(8574):1483-6.

A common error, often attributable to use of categorical x-axis, rather than quantitative.

More of this later …

Draw

n using MS Excel

Howie’s Helpful Hints

6. Emphasise the trivial

Source: US Bureau of Census. Social Indicators IIIcited: Wainer H. Visual Revelations (op cit)

Howie’s Helpful Hints

7. Jiggle the baseline

Source: Results of 1984 New York Democratic primary election;cited in: Cleveland WS. The Elements of Graphing Data. Monterey:

Wadsworth, 1985.

Howie’s Helpful Hints

8. Austria first!

Source: US Bureau of Census. Social Indicators IIIcited: Wainer H. Visual Revelations (op cit)

Drawn using Excel only

Note the “hatched” axis, ignoring the clear loss of proportionality for bar-lengths

Howie’s Helpful Hints

9. Label illegibly, incompletely, incorrectly

Source: Ithaca Times, 7 December 2000cited: http://www.math.yorku.ca/SCS/Gallery/, 21 Nov 2002

Howie’s Helpful Hints

10. Make it 3D!

Source: The Scientist 11[14]:8, Jul. 07, 1997cited: http://www.math.yorku.ca/SCS/Gallery/, 21 Nov 2002

Proportion of the Total Number of Published Papers By Region in All Fields, 1981 - 1996

Source: Marmot M. From Black to Acheson: two decades of concern with inequalities in health.

Int J Epidemiol 2001; 30: 1165-1171

Howie’s Helpful Hints

Good 3D & Bad 3D

The population of Sweden from 1750-1875 by age groups by Luigi Perozzo, from the Annali di Statistica, 1880,