Nobel Laureate Herbert Simon, in a 1969 article entitled “Designing Organizations for an Information-Rich World”, points out the problems created by the wealth of information.

A rabbit-rich world is a lettuce-poor world. [...] Now, when we speak of an information-rich world, we may expect, analogically, that the wealth of information means a dearth of something else – a scarcity of whatever it is that information consumes. What information consumes is rather obvious: it consumes the attention of its recipients. Hence a wealth of information creates a poverty of attention, and a need to allocate that attention efficiently among the overabundance of information sources that might consume it.

Let’s step back from this world view, down to the ballroom where the scientist presents. The problems are similar. During a presentation both presenter and slides are competing for the attention of the audience. Attention, Herbert Simon points out, is not easy to divide.

Human beings are essentially serial, 0ne-thing-at-a-time devices. If they attend to one thing, they cannot simultaneously, attend to another.

Expecting the audience to discover alone how to connect what is heard with what is seen on an information-rich slide, is expecting far too much! Discovering which area on the slide is alluded to by the speech, requires much attention. Because attention, like the time it requires, is scarce, little attention is left for the later (and much more important)  stage of knowledge extraction from the message content. By the time the audience is ready to process the information, the presenter will often have shifted to a new area of interest. And the twain do not meet!

Matching what the eyes see with what the ears hear is not simple. It is not just a matter of helping the eye focus on the area being described (although it helps). The audience has to be familiar with the vocabulary and symbols used, and has to have prior domain knowledge before being able to match oral information with visual information. For example, display multiple colorful shapes on a screen, say a blue dodecagon, a red circle, and a green cone,  and ask the audience: focus on the polygonal shape with an infinite number of sides, and whose shape reflects light in the 620-670 nanometer range. The audience is presumed to have sufficient prior knowledge to identify the shape. But how learned is the audience? How much of the vocabulary used by the presenter is understood by the audience? And what is wrong with “look at the red circle”.

What can we learn from the time-bound antagonistic relationship between attention and information-rich slides?

1) Help the audience visually identify the object requiring people’s attention using the simplest possible vocabulary before you talk about this object, in order to minimize the demands on what will always be a limited attention pool.

2) Decrease the amount of information on a slide (by layering, pruning, or condensing) to a level that allows the audience to have more time to pay attention to what you say because it has less to look at, in a given amount of time.

3) Confine your oral comments to what is visually singled out –  To be matched, oral and visual information require co-location of attention. Synchronize the two. Do not digress.