Source: Example of Pie Chart http://www.beaconlearningcenter.com/weblessons/kin... Example of Thematic Graphic, Wikimedia Commons, Creative Commons Example of Referent Graphic, Fair Use http://www.walkscore.com/score/510-central-ave-hot...
A callout is a small bit of text attached to a line or graphic pointing to its referral.
Edward Tufte is a Yale Professor who pioneered the field of infographics.
Information graphics is a design practice that presents data visually; this may consist of a simple ratio pie chart to condensing large amounts of complex data into visually digestible formats.
A referent graphic is an icon that refers to an element within the infographic, where the reader can easily surmise information by looking for a specific part of the data.
A thematic graphic is when the actual graphic presenting the data is labeled by color, shape, form, line, or dots.