Visualization Week 8

What is Data Visualization? A picture can say a thousand words (Chinese proverb) Data visualization is the use of tools to represent data in the form of charts, maps, tag clouds, animations, or any graphical means that make content easier to understand. Creating a picture in your mind Interpreting data in visual terms Raw data is too complex Not a substitute for statistical analysis or other quantitative methods Exploit visual perception to amplify cognition

criteria of visualization Creating a story with the data It should be based on data Focus on content than graphics Integrate statistical and verbal information Reveal data at several levels of detail It must be readable and recognizable Should produce an actionable insight Avoid distortions

Why visualization is effective Short attention spans Information overload Easy to grasp format More retention

Tufte - Minard's Napoleon's March to Moscow

Maximize data-ink ratio Tufte’s Measures Data ink ratio = Data ink Total ink used in graphic Maximize data-ink ratio Maximize data density Data density of graphic = Number entries in data matrix Area of data graphic Measuring Misrepresentation  close to 1 Size of effect shown in graphic Size of effect in data Lie factor =

Stock market crash? Example 500 475 450 1998 1999 2000 2001 2002

Example 500 250 Show entire scale 1998 1999 2000 2001 2002

Example 500 250 Show in context 1960 1970 1980 1990 2000

“Lie factor” = 2.8 Error: Shrinking along both dimensions

Examples of visualization Telling a story with the data!

Where Google street view is available

Tools Excel Tools – charts, histograms, pie charts Heat Maps One dimensional, and not useful to represent complex data Heat Maps Infographics Social Media Visualization Visualizing World Bank Data http://data.worldbank.org/products/data-visualization-tools Other tools Google Trends Fusion Tables Tibco Spotfire Twitter Analytics for Excel 2013

Heat Map Graphical representation of data in a map or a matrix Using colors instead of numbers Different colors denote different intensities or categories Tools Open heat map (http://www.openheatmap.com/)

Infographic Present information using visual tools According to visual.ly visualizations that present complex information quickly and clearly visualizations that integrate words and graphics to reveal information, patterns or trends visualizations that are easier to understand than words alone visualizations that are beautiful and engaging Tools Infogram Visual.ly

Social Media Visualization Big Data Analytics is only one aspect of social media Story telling through visualizations is the key Easy to get lost in pure numbers Online conversations Sentiment analysis Reviews and ratings Feedback Online networks Influencers

Twitter Analytics for Excel 2013 Demo

Twitter Analytics

Social Networks Connections between people Applications How many? Who? One way or two way? Intensity of connections? Applications LinkedIn InMaps (inmaps.linkedinlabs.com) Klout Score How Google allotted the first set of Google glasses?

Inclass exercises Tableau Openheatmap LinkedIn InMap TwitterStream

Links TED Talk on Data Visualization http://video- subtitle.tedcdn.com/talk/podcast/2010G/None/DavidMcCandless_2010G-480p- en.mp4