Sparkline Graph

September 22nd, 2007

Thirty weeks of activity in a glance

Edward Tufte described a sparkline, a term he coined, as “data-intense, design-simple, word-sized graphics.” They have been embraced by a number of information visualization buffs, and now a sparkline graph showing the weekly activity of Burrowowl.net appears next to the search tool. With two axes and shading, the following is all conveyed in a glance:

  • Each bar’s height represents the quantity of article written to this site.
  • Each bar’s color indicates the quantity of comments, darker bars representing more discussion, lighter bars representing less. The most recent week is set in red to draw attention to it.
  • Each bar represents one week of posts.

No explicit scale is shown; all heights and colors are relative to the other data. Graphs of this sort are meant to be read and understood immediately, much like a natural word is more quickly-absorbed, understood, and put into context than an acronym or unfamiliar jargon. If you see a row of tall bars followed by a dip, it means that I was slow in posting during that period of time compared to normal. If you see a dark splot of bars amongst very light ones, those were times of more frequent discussion.

Hat tip to Information Aesthetics for calling my attention to this form of informational graphic and putting a name to them so I could look around for the proper tools, and hat tip to Sean McBride for writing the PHP that actually generates the graphic.

Currently I’m showing 26 weeks, half a year, though that may change. Sean McBride’s WordPress plugin can operate out of the box at daily, weekly, or monthly granularity, and is quite configurable.

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