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Data Presentation Standards“Graphical Excellence” -- Edward Tufte
• well-designed presentation of data of substance, statistics and design
• complex ideas communicated with clarity, precision and efficiency
• the greatest number of ideas in the shortest time with the least ink in the smallest space.
Best example: Baseball statistics
Defense presentation at John Gotti trial:
C R I M E C A R D I N A L E L O F A R O M A L O N E Y P O L I S I S E N A T O R E F O R O N J Y C U R R O
MURDER X XATTEMPTED MURDER X X
HEROIN POSSESSION AND SALE X X X XCOCAINE POSSESSION AND SALE X X X
MARIJUANA POSSESSION AND SALE XGAMBLING BUSINESS X X X
ARMED ROBBERIES X X X X XLOANSHARKING X X
KIDNAPPING X XEXTORTION X X
ASSAULT X X X XPOSSESSION OF DANGEROUS WEAPONS X X X X X X
PERJURY X XCOUNTERFEITING X X
BANK ROBBERY X XARMED HIJACKING X X
STOLEN FINANCIAL DOCUMENTS X X XTAX EVASION X XBURGLARIES X X X X
BRIBERY X XTHEFT: AUTO, MONEY, OTHER X X X X X
BAIL JUMPING AND ESCAPE X XINSURANCE FRAUDS X X
FORGERIES X XPISTOL WHIPPING A PRIEST XSEXUAL ASSAULT ON MINOR X
RECKLESS ENDANGERMENT X
CRIMINAL ACTIVITY OF GOVERNMENT INFORMANTS
Meaningful Data
• Count
• Divide
• Compare
Meaningful Data (contd.)
• Use rates, ratios and per capita measures rather than aggregate totals.
• Two time points are better than one.– Show change over a meaningful time
period. (5 year change rather than annual change).
– Multi-year trends are best presented in time series charts rather than tables.
• Show the source of the data
Rates and Ratios
Two times points are better
Bad Tabular Display
Draw Conclusions from Meaningful Comparisons
• One year changes in crime rates are not very meaningful
• Rates (and averages) tell more than counts(crimes rates, not crime counts)
Unambiguous Data
• Each number in a table should have a precise meaning.– Use titles, headings, and notes to clearly define
the data.
• Be precise when using rates and ratios– Clearly define the numerator and denominator of
the measures
• Be clear about percent change, net percentage change.– Abortion rate vs. Abortion ratio– % of poor vs. the % that are poor– Net change vs. % percentage change
Unambiguous Data
Change in Teenage Birth Rates: 1987-1998
White 6.7%Black -4.9Asian -1.8Hispanic 3.7
Source: Statistical Abstract 2000, table 85
Efficiency
Data can be quickly interpreted by the reader.– Sort data on the most meaningful variable– Time always left to right– Similar data goes down the columns– Highlight important comparisons– Don’t force comparisons between two different
tables– Consistent formatting across tables
Do not sort alphabetically
American League East StandingsW L PCT GB
Baltimore 51 75 0.405 27.5 Boston 72 53 0.576 6 New York 78 47 0.624 - Tampa Bay 69 56 0.552 9 Toronto 57 67 0.460 20.5
Sort data….
Sorting data by least meaningful variable
Time goes left to right……………….
Variables define the columns
Variables define columns………
Highlight critical comparisons….
Highlighting
Comparisons
0 - 1year
0 - 5years
1 - 5years
Sweden 3.2 4.0 0.8 Austria 4.4 5.4 1.0 Finland 3.7 4.7 1.0 France 4.2 5.2 1.0 Japan 3.2 4.2 1.0 Switzerland 4.1 5.1 1.0 Belgium 4.2 5.3 1.1 Greece 6.7 7.8 1.1 Italy 5.0 6.1 1.1 Spain 4.2 5.3 1.1 Canada 4.8 5.9 1.1 Germany 4.3 5.4 1.1 Norway 3.3 4.4 1.1 Australia 4.4 5.6 1.2 Netherlands 4.7 5.9 1.2 United Kingdom 4.8 6.0 1.2 Ireland 4.9 6.2 1.3 Poland 6.7 8.0 1.3 Denmark 4.4 5.8 1.4 Cuba 5.1 6.5 1.4 New Zealand 5.0 6.4 1.4 United States 6.3 7.8 1.5 Portugal 5.0 6.6 1.6Source: United Nations World Population Prospects Report, 2006
Age Group
Table 1Infant Mortality Rates, per 1,000 live births,(circa 2005-2010)
Excel skills
• Combine cells for title, use word wrap
• Adjust cell widths
• Sort data
• Use formulas and copy formulas
• Do not use too many fonts
• Decimal places: 2 significant digits
• Horizontal borders
• Copy image to Word
