Taking advantage of Preattentive Processing in your visual aids

The article Data Presentation: Tapping the power of visual perception, by Stephen Few, deals with the question “why do some people respond well to some forms of data representation and not others” This is definitely worth reading for anyone involved in representing data in a visual medium. The article discusses such topics as the role and limitations of memory in our interpretation of charts and data and the fundamental attributes of sight and how these are related to attentive and pre-attentive processing.

Attentive and pre-attentive processing were new terms for me, but they put a name to some ideas that I have had in the past and which are also closely related to concepts of ‘layered meaning.’

The authors illustrate the difference between attentive and preattentive processing through the use of two illustrations.

figure 1

figure 2

In Figure 2, discerning how many times the number ‘5’ appears is relatively easy because it has been distinguished by colour – a preattentive attribute that differentiates it from other numbers. In contrast, discerning the frequency in Example 1 is much more difficult because the brain must work harder to discern the individual shapes (the difference between a ‘3’ and a ‘5’, for example).

For presenters and infographic designers, this is an important concept to keep in mind, and further underlines the importance of using preattentive attributes (color, orientation, size, line width, etc.) to draw attention to the key ideas and data points (see discussion on tables). 

Sources:

• The full text of the article is here and here in pdf.
• A detailed description of preattentive visual attributes is at the bottom of the second page.