The PowerPoint Glass Barrier separating audience and presenter

New England Journal of Aesthetic Research
New England Journal of Aesthetic Research

You are supposed to be close and personal, and upfront… but up front, facing the audience, things are not close and personal. It’s them versus you: them sitting and listening, and you standing and talking next to your faithful computer FIFO and its wireless leash. But the one on the leash is you. If you strand too far away, FIFO will radio you back to base, or bite you with its one and only bluetooth. That impalpable wall between you and the audience is a barrier, granted, more of a psychological than a solid one, but a barrier nonetheless.

Imagine what might have happened had you untangled yourself from FIFO’s leash. Actually, you don’t have to. Andrew Askew, Assistant professor of Physics, Florida State University has done it and this is what he says.

“The use of the PowerPoint slides was acting as a straitjacket to discussion. […] We removed the PowerPoint slide, and like a big glass barrier was removed between the speaker and the audience. […] The communication became a lot more two-way instead of just the speaker speaking at length for 15, 20 minutes. The audience really started to come alive, to look up from their laptop computers and actually start participating in the discussion, which is what we were really trying to foster.”

(  from an interview by Alan Yu on all tech considered NPR radio )

The scientific presentation is a way for the scientist to get feedback on his or her work, to start a discussion. When will PowerPoint become fully interactive? When will audience input appear on the presenter slide (through their phone or tablet PowerPoint app)? When will presenters start interacting with the data on their PowerPoint slides with the existing but rarely used electric pen? When that day comes, when PowerPoint comes of age, maybe Jeff Bezos and Jeff Weiner will celebrate its return in their company meetings. For now, for them, the fabled passivating presentation tool is persona non grata.

Nothing reveals personal expertise better than questions; therefore,…

Image source: Flickr; Author :Tintin44

They were certain that their expertise would be seen through the high density of information on their slides. They were certain that removing an ounce of proof would be like losing a pound of flesh – a tragedy of Shakespearian dimension. They were certain that confidence displayed would translate into expertise perceived. But their certainties were rational myths.

Slides never proved expertise. 1) Slides prepared by an expert may be presented by a non-expert. 2) Junior scientists not yet familiar with a field of research tend to densely pack facts and points on slides so as not to forget (mentioning) them. The more a presentation looks like a condensed version of a paper (for example by keeping the reference to figures used, or by packing on one slide all the visuals illustrating a point), the more the presenter may reveal lack of expertise. Why? An expert’s understanding of a problem is such that, what is principal claim, what is central proof, and what is key impact, are easily identified. An expert can easily unpack a slide; A non-expert can’t.

Confidence never proved expertise. 1) Multiple rehearsals give most presenters a higher level of confidence which leads to a smoother delivery – regardless on their level of expertise in the presented topic. 2) Over-confidence often marks ignorance. You only know that you don’t know when you know enough. Superficial knowledge may give you undue confidence. 3) Lack of scientific expertise cannot be inferred from the nervousness of a presenter.

Correct answers to unprepared questions prove personal expertise. It is through the Q&A following a slide presentation that the  presenter reveals the extent of his or her expertise. The unpredictability of questions and the presence of other experts in attendance guarantee it – for indeed, it takes an expert to identify an expert.

In conclusion, do not try to establish your expertise through packed slides. Let it shine during the Q&A session. But for that, you need to make sure that you have time left to answer questions! Indeed, finish slightly early so that you have more Q&A time. And when one asks a question, do not answer at length, thus wasting the opportunity to be asked more expertise-revealing questions, and to identify other scientists interested in your work.

Oh, and one last thing… An expert never answers a question with “I think”. An experts knows.

I Think, Therefore I Am…. Not an Expert (non-existentialist ending to the famous René Descartes quote)

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

010 Powerpoint and Shakespeare

What is the potential of PowerPoint, or for that matter, the potential of any software used in presentations? Does PowerPoint present an improvement over other methods of presentations? What is the danger of PowerPoint?

Find out from our presenter experts, Dr Alastair Curry and Dr Mark Sinclair.

Pan through images with PowerPoint

Pan through an image with PowerPoint (video)

With this technique the presenter moves seamlessly and precisely inside a document larger than a slide by imitating a camera panning through the document, as if the hand moved a transparency across an overhead projector (Powerpoint inch-based offset technique).

Scaling a group image+ text – PowerPoint & Keynote

Scaling objects in PowerPoint and Keynote (video)

To resize a group that includes image and text, the group must first be converted to an image; alternatively, the group can be ungrouped and text can be be resized separately from the image.It is possible to reduce the decrease in legibility associated with vertical or horizontal downsizing by choosing a font of the appropriate type. This technique is useful to prepare a conclusion slide containing scaled-down visual reminders of what was presented on earlier slides. It is also useful to ease comparison by refreshing people’s memory via a scaled-down version of a previously shown visual.

Visible map and invisible shortcuts – navigation tools

The Map Slide (video)

“Keep to time” is good advice, but how? Since slide contents are the greatest time-consuming factor, it makes sense to adjust them until the presenter no longer faces the approaching wall of time with the fear of crashing into it. However, despite the best of intentions and preventive content pruning, the unexpected may bring that dreaded wall closer: an unplanned digression, a forced late start, or an improbable interruption maybe. Is the presenter ready for the unexpected? tools, such as hyperlinks and map slides demonstrated on this video, help the presenter manage time better.

The map slide is best used for long presentations. It helps the audience track your progress while revealing the overall structure of your talk. Hyperlinks are usually invisible doors (buttons, objects linking to other slides in your presentation) that allow the presenter to skip slides without the audience noticing it (thus saving time), or to insert slides on the fly as it were to answer some live questions during the talk (thus adding time).

All tools have intrinsic limitations. Hyperlinks and map slides are no exception.

The map slide (also called outline slide) is not useful in short (10-15 minute) presentations where it is preferable to go straight into your story after the audience has been hooked into it.

Hyperlinks force you to use a presentation remote with embedded mouse because you have to click on them to activate them. Without that, you are on a short leash. You are required to stand close to the lectern where your computer mouse is; this may not be the most advantageous position on the podium to host your guests scientists.

Hyperlinks, if numerous, create a labyrinth where the Minotaur (and you) could easily get lost (remember these links are supposed to be invisible).

hyperlinks gone wild

You want hyperlinks to remain invisible, so that the audience is not aware of your emergency shortcuts. But this great asset is also a great liability if you do not remember where you have hidden your precious links.To make matters worse, Microsoft PowerPoint hides non-text links in slide creation mode (thankfully, Keynote does not).

A Hyperlink is half witted.  Imagine you had to cross a hot stream by jumping from one stepping stone to another. If I were to remove one of the stepping stones, you would not jump. Microsoft PowerPoint 2008 for Mac jumps, landing you into hot water regardless (taking you to the wrong slide – the one with the same number as the removed slide). Smarter Apple Keynote ’09 disables the hyperlink.

Dangling Hyperlink gets attached to wrong slide in PowerPoint 2008

A Hyperlink is half smart because it keeps pointing to a slide even when you change the order of that slide in your presentation.

Link continues to point to slide even after slide is moved to another place in the presentation

Animate using motion path or action builds


Motion Path animation (PowerPoint)

The oral presentation surpasses the journal paper in many respects, but surely, one of the key differentiators has to be the use of animation to explain. Finally, a method can come alive on your screen whereas, on paper, it is mummified, embalmed in the  sarcophagus of a diagram. Microsoft PowerPoint and Apple Keynote enable you to put objects in motion. Trace a linear or curved path and have the object follow that path at a speed, acceleration and deceleration set by you. Decide on an angle and have the object rotate to that angle, fix a size and have the object grow or shrink to that size, set a transparency level and have the object gain opacity or transparency. Combine all these actions together (yes, it takes the skills of a choreographer sometimes), and you can resuscitate the dead… diagram, that is:)

A word of warning: Animations take time to build. It is not unusual to spend  an hour on a 30 second animation. But the results are beyond your wildest expectations. You, the presenter, will be a cut above the rest.

Use animations in the following circumstances:

Whenever you feel like using your hands and making gestures to explain something (this does not apply to Italians who feel like that all the time).

Whenever you want to describe the path followed by something in motion (an ion, electron, light, virus,…) through something else (a porous barrier, a membrane, a conductor, an optic fibre,…) over time, or over a number of sequential steps.

Whenever you want to guide the eyes of the audience to a succession of specific places on the screen without using the distracting laser pointer (yes, I don’t like red laser polka dots, and I’ll explain why in another blog entry).

Whenever you want to represent objects whose speed, acceleration, shape, action, colour, or transparency changes when time passes or when these objects interact with other objects.

Whenever else you deem necessary to explain something faster and more clearly, or more interestingly.

Do not use animations in the following circumstances:

You have not yet mastered PowerPoint Motion Path techniques, or Keynote’s actions.

When you have no good reason to use animation (gratuitous), but you just like it, and want to work for Disney or  Pixar.