The Context of Data Visualization - Data Visualization: A Successful Design Process - page 20

Take another example, which portrays the key events in a couple of soccer matches
showing completed passes (green lines), shots (blue triangles), and goals (red dots)
as shown in the following image:
Image from "Umbro World Cup Poster" ( http://www.mikemake.com/Umbro-s-World-Cup-Poster ),
created by Michael Deal
Once the reader has mastered the understanding of what each shape and its position
means, these displays provide a powerful and rewarding insight in to the key
incidents and the general ebb and flow of each game.
In simple terms, so long as you can avoid all the negative characteristics that Edward
Tufte mentions at the top of this section, you should succeed in giving people an
accessible route in to the data. Make sure that the efforts needed from the reader or
user to understand how to use and interpret a visualization are ultimately rewarded
with a worthy amount of insight gained.
Never deceive the receiver
Visualization ethics relates to the potential deception that can be created, intentionally
or otherwise, from an ineffective and inappropriate representation of data. Sometimes
it can be through a simple lack of understanding of visual perception.
In the following diagram, we see a 2D pie chart and a 3D version. When the eye
interprets a graphic like this, what it is actually doing is perceiving the proportion
of visible pixels:
Image from "The Curious Incident of Kevins in Zurich…and other stories"
( http://www.researchobservatories.org.uk/EasysiteWeb/
getresource.axd?AssetID=38334 ) by Alan Smith.