|InfoVis.net>Magazine>message nş 156||Published 2004-11-15|
|También disponible en Espańol|
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When we think about a graphic, like for example a bar or pie chart, we tend to consider them as auto consistent entities, separated from their environment be it textual or not. But this isnâ€™t necessarily so or probably convenient either.
Edward Tufte calls Sparkline to â€śIntense, simple, word-sized graphicsâ€ť. The reason for this name is the vivid and active role they play within text. Many names have been tried including bonsai graphics, but I prefer the term word-like graphics or just Sparklines to preserve Tufteâ€™s word
Hence, a sparkline is a conventional graphic reduced to a size equivalent to that of one or a few words, integrated in the text as another word.
To understand its utility, letâ€™s consider a sports example. Letâ€™s suppose that we are talking about the soccer season of the Spanish league 2003-2004. We want to compare the results of the two most important (and on the other hand bitter rivals) teams. We can show the results of both teams as a set of positive bars of fixed length when they win, negative when they lose and with a dot in case they are level on points. This allows us to include in the text extensive information about the 37 weeks of the league that, would otherwise occupy a big table of considerable size.
The Spanish league last year began with a crisis in F.C. Barcelona that was over right after the election of a new president of the club, while Real Madrid began very well but ended losing match after match.
On the other hand we could create a table comparing both teamsâ€™ results by placing their respective sparklines, one on top of the other, to show which week one team won and the other lost.
Another interesting example is the evolution of the market of several big players of the IT business like Apple, Cisco, Dell, IBM, Microsoft, Oracle, and Sun, whose compared evolution can be seen in the next table.
The expressive power of these mini-graphics relies on their integration with the remaining text on one side and with their relative dequantification on the other.
In his website, Tufte discloses the draft of the chapter on sparklines heâ€™s preparing within the framework of his new book â€śBeautiful Evidenceâ€ť. In it we can find several examples of what these entities are, along with their applications and utility.
According to Tufte the practical production of sparklines requires taking into account some aspects regarding design and construction:
Sparklines arenâ€™t new. Tufte shows several wonderful examples of Galileoâ€™s documents where small graphics show, together with the adjacent words, how planets like Saturn can be seen through the telescope. Neither are they of an essentially different nature compared with the conventional ones except for their dimensions and the context they operate in.
Nevertheless, considering them as an entity with their own character opens up new doors to both graphical and written expression.
Another interesting sparkline made by James Byers shows the evolution of the US deficit from 1983 to 2003. During all that time only the last years of the Clinton era and first of Bush were in positive figures.
Many thanks to J. Byers for his help and for adding features to his library for this occasion.
Other interesting links:
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