25. Principles of Graphical Integrity Data Representations proportional to Data Real dollars, instead of deflated dollars #Dimensions in graph = #Dimensions in data Provide context
58. Takeaways Maintain Graphical Integrity Minimize Data-Ink Ratio, within reason Avoid Chartjunk Use Multifunctioning Graphical Elements, if possible Keep Labels with data
Hand-drawn graph from the 1880’s, showing Paris train schedule.Attributed to the French engineer Ibry.Source: E.J. Marey, La Methode de Graphique (Paris, 1885)
William Playfair (1759-1823)3 series over time:-Wheat prices-Labor wages-Monarch
From 1960 census:# of families per county with very low income (<$3,000)# of families per county with very high income (>$10,000)
Charles Joseph Minard, French Engineer, 1781-1870“It may well be the best statistical graphic ever.” – TufteTan line = Napoleon’s march to Moscow in the winter of 1812. (422,000 men – 100,000 men)Black = Napoleon’s retreat to Poland. (422,000 men – 100,000 men)Width of lines represents size of army. (100,000 men - 10,000 men)Bottom line is linked to lower graph, showing dates and temperatures (very cold winter)Auxiliary troop movements are shown.Crossing Berzina River was a disaster.Variables: -Size of army -Location -Direction of movement -Temperature -Dates
From NY Times, 1978Fuel economy standards increased by 53%Graphic shows fuel economy increased by 783%Lie factor = 14.8
From NY Times, 1978Fuel economy standards increased by 53%Graphic shows fuel economy increased by 783%Lie factor = 14.8
From TheLos Angeles Times, 1979Lie factor = 2.8(also horizontal spacing of X-axis is wrong)
Time, 19791-dimensional data is shown as 3-dimensional objectsIncrease of 454% is shown as volume increase of 27,000%Lie factor=48.8, a record!
Source: Washington Post, 1979Graphic suffers from bias of 2-dimensional figures representing 1-dimensional data points.But also represents Nominal dollars – not Real (or inflation-adjusted) dollars
Source: Sunday Times (London), 1979
New York Times, 1978
Data-ink = ink that directly shows the data and will result in loss of data if erasedAll else = decorations, metadata and redundant data.Proportion of a graphic’s ink devoted to the non-redundant display of data-information.1.0 – proportion of graphic that can be erased without loss of data-information
Duck-shaped building in Flanders, NY3 types of chart junk:1) Unintentional optical art2) Grid3) Self-promoting graphical duck
Moire’ EffectGraphic appears to vibrate or shimmer
