Data Visualization Visualization Taxonomy & Statistical Graphs - PowerPoint PPT Presentation

Data Visualization Visualization Taxonomy & Statistical Graphs Azalea Vo Alexander Lex avo@college.harvard.edu alex@seas.harvard.edu xkcd

Administrivia • Thursday: guest lecture on Tableau Jock D. Mackinlay • Friday: Tableau and ManyEyes lab Blake and Shirley • Readings for this week Chapter 1

Homework 2 • Topic: • Project 1 proposal! • Advanced web scraping • Working with APIs • Look at lecture 3 (Ian) and Friday‘s lab Lab video: http://tinyurl.com/cs171lab1video Sources: http://tinyurl.com/cs171lab1

Project I • Has to use data you scraped yourself! • Update your Process Books continually • Your choice of visualization tools • We support ManyEyes and Tableau

Design Critique Learning Catalytics Session ID 118785 http://mariandoerk.de/edgemaps/demo/

Comparisons

Bar Chart How Much Does Beer Consumption Vary by Country? Bottles per person per week

Length VizWiz Blog

Direction Nicolas Rapp

Negative Values US Department of the Treasury "The Financial Crisis Response In Charts"

Naveen Sinha, 2009

Waterfall Chart VizWiz Blog

3D Few, “Show me the Numbers”

Excel Charts Blog

Employment Law HQ Blog

Bullet Graphs http://en.wikipedia.org/wiki/Bullet_graph

Bars vs. Lines Line implies trend. Do not use for categorical data. Zacks 1999

Relationships

Dot Plots

De novo mutations revealed by whole-exome sequencing are strongly associated with autism Sanders et. Al Figure: Identification of multiple de novo mutations in the same gene reliably distinguishes risk-associated mutations. Nature , May 2012

Proportions

WILLIAM PLAYFAIR 1759-1823 2

Pie Charts

Total: 104% VizWiz Blog

Showing Change v.s. VizWiz Blog

Showing Change v.s. VizWiz Blog

Coffee Drinks Illustrated The Perfect Pour

3D Pie Charts Few, “Show me the Numbers”

Why 3D pie charts are bad Kevin Fox

Green vs. Purple

Fox News, 2009 wikipedia.org

No Comments...

Donut Chart The Economist Daily Chart

Total % ? WSJ Graphics Blog

Stacked Bar Chart Few, “Show me the Numbers”

Storytelling with Data Blog

Small Multiples Peltier Tech Blog

Stacked Area Chart Asymco

JOSEPH MINARD 1781-1870 4

Stacked 100% Area Chart Flowingdata, Changes in Consumer Spending

v.s. leancrew.com & Practically Efficient

Area as Intersection WSJ Graphics Blog

WSJ Graphics Blog

http://maryandmatt.net/

Summary: Comparison, Proportions

Ivan Cash

Visualization Taxonomy

Motivation Useful Junk? The Chartjunk Debate

Visual Literacy Periodic Table

Melanie Tory and Torsten Moller, Infovis04 Jeffrey Heer and Ben Shneiderman, ACM

Distributions

Histogram ggplot2

Population Pyramid – A Histogram [Wikipedia]

Bin Width binwidth = 0.1 binwidth = 0.01 ggplot2

Density Plots

takeasweater.com

Box & Whisker Plots Few, “Show me the Numbers”

ggplot2

Correlations

Scatterplots http://xkcd.com/388/

Scatterplots ggplot2

Don‘t [Spotfire]

Box Office Quant Blog

Overplotting ggplot2

Overplotting alpha = 1/10 alpha = 1/100 ggplot2

Binning http:// vis.stanford.edu/projects/datavore/splom

Trend Lines ggplot2

Residual Graph • Plot vertical distance from trend line [Cleveland 85]

Trend Lines NY Times, March 2009

Quadrants http://www.asymco.com/2010/10/05/the-symmetry-of-share-shifts-in-mobile-phones/

Relative Changes Junk Charts

Path Plots New York Times

Trends

WILLIAM PLAYFAIR 1759-1823 85

JOSEPH MINARD 1781-1870 86

Yahoo! Finance

Data & Trend Plot The Daily Dish

Trend Histories New York Times, Porcupine Graphics

Trend Projections Washington Post

Russell Investments

Design?

Fox News flowingdata.com

Aspect Ratio & Scales

Aspect Ratio Yearly CO2 concentrations [Cleveland 95] Slide based on J. Heer / M. Agrawala

Banking to 45  [Cleveland] Two line segments are maximally discriminable when their average absolute angle is 45° • Optimize the aspect ratio to bank to 45  Slide based on J. Heer / M. Agrawala

Banking to 45 Degrees Aspect Ratio = 1.17 CO 2 Measurements William S. Cleveland Aspect Ratio = 7.87 Visualizing Data Slide based on J. Heer / M. Agrawala

Non-Zero Based Scales Few, “Show me the Numbers”