Scientific Presentations and Chinese Proverbs – part 2

Source: Flick; Author: Rob Well.

“A road is traced by the people who walk on it.”

Acknowledge others, the people who inspired you, gave you ideas. There is always a way to acknowledge someone in a presentation. Your road may still be a path, but someone cleared some branches already!

“what touches cinnabar turns to red, what touches ink, turns to black.”

A presentation is made from a painter’s palette. With distinct colors, you create a blend, a color gradient. Each new slide is different yet never far apart from its neighbors. Each new slide is fluidly linked to other colors in the palette. Work on your oral slide transitions. Avoid discontinuitiesUse B keys or black slides also.

“An ax cannot hew it’s own handle.”

Your main concern is to have others use what you have discovered. You provide the steel, they provide the handle. Your presentation should conclude with a clear statement of the significance of your work for others – their handle.

“One lie only, and one hundred deeds are now in doubt.”

In presentations, whatever you declare upfront to describe the significance of the problem and the need for a solution, has to be unquestionable, credible, rock solid. Any exaggeration (lie by amplification), or omission (lie by hiding), and your audience will now have reservations and treat your future claims with scepticism.

“No sooner has someone come that satisfaction is due.”

The audience had a choice not to attend your talk. People have come for a reason. Understand why they came, what they need, and satisfy them. You are now in debt.

“Better act with your hands once than to look with your eyes a thousand times.”

How does an audience act with hands during your talk? People raise arms  to ask questions. Each question is an opportunity for the deeper understanding that precedes adoption and action. Always leave ample time for questions. An audience who only looks at slides without moving to the next stage – is worthless to you. And by the way, use your hands, stretch them in an open gesture to ask for questions, don’t just look at the audience waiting for questions!

By Jean-luc lebrun

continuity bugs in linear slide presentations

Whenever you take a non linear media and flatten it (make it linear), you introduce problems of two kinds:

1) Discontinuities in logic. The audience needs to remember what was connected to what, earlier in your presentation, to see the connection logic.

2) Discontinuity in time. As time passes, the audience remembers less and less of what they heard and saw. As a result, the memory fails to reconnect the time-broken strands of a disrupted argument.

Here is an illustration. Each square represents a slide. The slides are numbered from 1 to 5. The eroding effect of time on memory is here symbolized by the greying of colours, from dark (last slide best remembered) to grey (started to fade in memory) to dotted line (first slide, may have been presented 8 to 10 minutes before slide 5, vague or no longer remembered).

flattening problems

I assume here that all slides are equal in duration. Things worsen when slides are text heavy. We have all encountered slides that are so dense in information and take so long to explain that the audience has forgotten what was said at the beginning of the slide by the time the end of the slide is reached!

So here is my tip:

Visualize the logical connections between your slides, either as a domino or a graph. This will help you identify the potential memory-related problems your audience may face. And apply one of the following solutions to remove these problems.


The Announce technique consists in telling the audience what will be covered in the next (two) slides. The audience, once alerted, finds it much easier to keep the information of slide 1 in memory and relate it to slide 2 and 3.

The Repeat technique simply re-presents past information so as to be able to refresh fading memory (like the refresh cycle that keeps RAM memory alive!)

The Merge technique consists in keeping on the same slide all related elements, presenting them one by one (one at a time) to avoid overwhelming the audience with too much information at once, but allowing people to see past information on the same slide. Naturally, this is only possible if the slide can contain these related elements without losing readability.

The Restructure technique, as its name indicates, looks at alternative structures that would enable the contents to be presented without discontinuities.


By Jean-luc Lebrun