Download - Visualizing Data
Visualizing DataJeff Arnold
April 9, 2013Emory University, Atlanta
Data Viz is EverywhereBusiness / EconomicsWeatherSportsFinance
OutlineExamples1. Florence Nightingale2. Challenger ExplosionWhat is it?How does it work?When doesn't it work?
Examples
Florence Nightingale
Challenger Explosion
What is DataVisualization?
Grammar of Graphics
Grammar of Graphics
Grammar of GraphicsGeometric Shapespointslinesbarstext
Aesthetics: convey informationx positiony positionsize of elementsshape of elementscolor of elements
Data and Aesthetics
How does itwork?
PATTERNSPATTERNSPATTRESNPATTERNS
Anscombe Quartet
Looking for Patterns
Expected DataActual DataPlots are Comparisons
When (and why)does it not
work?1. Too many variables2. Too many observations3. Perceptual biases4. Understanding randomness
Too Many Variables
Too Many Observations (I)
Too Many Observations (II)
Too Many Observations (III)
Visual Perception BiasesQ: What is the value of a b? Does it change?
Visual Perception BiasesA: a b = 2 everywhere.
Visual Perception Biases
Visual Perception Biases
Understanding RandomnessQ: In which plot were the points selected from a uniform
random distribution?
Understanding RandomnessA: The plot on the right.
ConclusionData visualization and statistics are complementary
Data visualizationintuitivecognitive biases
Statistical methodsunintuitiveovercome our cognitive biases
Questions?
References
Kimmo Soramaki, Morten L. Bech, Jeffrey Arnold, Robert J. Glass and Walter E. Beyeler (2007). "The Topology of
Interbank Payment Flows", Physica A.
Hadley Wickham (2010). "A Layered Grammar of Graphics", Journal of Computational and Graphical Statistics.
Nightingale receiving the Wounded at Scutari, By Jerry Barrett
Diagram of the Causes of Mortality in the Army in the East, by Florence Nightingale
Space Shuttle Challenger explodes shortly after takeoff.
Plot of GE vs. SP500 from Yahoo! Finance
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