Most people who browse websites covering presentation skills stumble on the maxim “Less is more“. Usually, this principle applies to the content of PowerPoint slides. Less slide (text) content to be read by the audience is seen as more beneficial to the speaker. As scientists, we should question everything, right?

Those of you who are LinkedIn members will find an excellent discussion on this principle in the “Presentation Gurus!” discussion started by Matt Gambino entitled “Ways to convince co-workers that “less is more” in PowerPoint”.

Generally, I agree with the “less is more” principle and promote it in my courses. Why? The more there is on a slide, the more that slide has separate areas of focus. The problem then becomes one of synchronicity between the oral comment of the speaker and the visual focus of the audience on the part of the slide that visually matches the oral comment. Perfect synchronicity is impossible in practice. Either we linger on points for which we have insufficient prior knowledge while the expert speaker moves on to other points. Or we disagree with the point made and stop following the other points, constantly returning our eyes to the point of contention. Or the speaker fails to verbally or visually identify on the slide the target where our attention should be focused, imagining that we are able to use our knowledge or his speech to figure it out by ourselves. Most of us, non-experts, can’t.  To reduce such synchronicity problems, presenters use layers, laser pointers, they introduce one bullet at a time, or they make each bullet become one slide. The problems are reduced, but not to the point they disappear!

So… Let’s start questioning the assertion “Less is more”, as scientists.

1) Is there a lower boundary to less under which less is less?

Clearly, one cannot push the limit past a certain lower boundary beyond which, slide support is no longer effective. The sketchy or vague information on each slide may become so cryptic that the oral comment is bound to go beyond the slide content, thus creating an attention divide between slide content and oral content.  Research shows that, in such situations, memory is less effective and brain activity is lesser than under full undivided attention (encoding slows down in the”hypoccampus, temporal and prefrontal cortex of the left hemisphere*”).

The lower boundary is also defined by the interdependencies within the points made on a slide. When a slide makes multiple inter-related pojnts, these points must remain on the same slide for the audience to see the interdependencies. In this case, less, would force the presenter to divide the slide into multiple slides, and that in turn would force the audience to remember the contents of the previous slides to be able to see the interdependencies. In reality, we don’t remember. Working on making slides independent of each other is a move in the right direction.

The lower boundary is also influenced by the gap between the prior knowledge level of the audience and the knowledge level expected by the speaker. If that gap is large, less “just in time” background information, results in less understanding.

2) Are there situations where, clearly, less is not more, but more is more?

I can think of at least four situations where this would apply:

If providing less contents does not fulfil the expectations your slide title raised in the audience (even the title of your talk), more is more as the speaker needs to meet the expectations that any slide title raises.

For the second situation, imagine a scientist with an accent so thick that the audience understands less than a quarter of the words pronounced. In this situation, the scientist could say less, and possibly read more or display more while giving ample time to the audience to read along and to figure out what the graphics contain since graphics are usually understood regardless of language for the most part.  They are vital when it comes to understanding and essential when it comes to convincing. In this case, the audio track is not essential as long as the video track is self-explanatory. More (legible) text on a slide would bring better understanding. Since the memory required to associate the sounds heard from the speaker with the written words on the slide is far too large, the audience rapidly gives up and reads.

A third situation arises when we consider that, since the lack of synchronicity is one of the causes for the “less is more” principle, the speaker can increase synchronicity by slowing down the pace, but also by adding arrows, circles, and other attention-calling methods such as callout boxes, colour /size change, animation, etc. In this case, more is more.

Lastly, my fourth example is inspired by an earlier comment of Ed Skarbek: more is more if you have access to more than one screen to visualize your information, and facilitate comparisons – assumed here is that the extra screens carry visuals, not just text.

I hope this provides a more balanced perspective to the “Less is More” maxim.

Image Flickr. Cesar Rincon. “There is no spoon”

“The Effect of Divided Attention on Encoding and Retrieval in Episodic Memory Revealed by Positron Emission Tomography”. Tetsuya Lidaka & Al,*Journal of cognitive neuroscience archive. vol.12. issue 2. March 2000,p267-280