How to write and publish a scientific paper - Barbara Gastel, Robert A. Day 2022

Slides
How to present a paper orally
Conference communications

At small, informal scientific meetings, various types of visual aids—including flip charts, whiteboards, and blackboards—may be used. At most scientific conferences, however, Microsoft PowerPoint presentations or the equivalent are the norm. Every scientist should know how to prepare effective slides and use them well, and yet almost any session at a conference quickly demonstrates that many do not.

Here are a few important considerations. First, slides should be designed specifically for use with oral presentations, with large-enough lettering to be seen from the back of the room. In general, use lettering that is at least 28 points in size. Choose a sans serif typeface, such as Arial or Calibri. Slides prepared from graphs that were drawn for journal publication are seldom effective and often are not even legible. Slides prepared from a printed journal or book are almost never effective. So, if necessary, re-create the content. Also, remember that, quite likely, some audience members will be colorblind. Therefore, avoid using solely color to distinguish items such as lines on a graph, beware of combinations of colors (such as red and green) that are hard for many people with colorblindness to distinguish, and follow other guidelines (for example, Collinge 2017) for accessibility to people who are colorblind.

Slides should be uncrowded. Each slide should illustrate a particular point or perhaps summarize a few. To permit rapid reading, use bullet points, not paragraphs. For text slides, try not to exceed about seven lines of about seven words each—or, stated another way, about 50 words in total. It has been said that if a slide cannot be understood in 4 seconds, it is not good.

Beware of showing too many slides. A moderate number of well-chosen slides will enhance your presentation; too many will be distracting. One general guideline is not to exceed an average of about one slide per minute. If you show a slide of an illustration or table, indicate its main message. As one long-suffering audience member said, “Don’t just point at it.”

Speaking of illustrations and tables: If there are findings that you can present in either a graph or a table, use a graph in an oral presentation. Doing so will help the audience grasp the point more quickly. And speaking of pointing: If you use a laser pointer, take care with it. In your enthusiasm or in distraction, do not wildly gesture at the slide—or the audience—with a lighted pointer. Rather, turn on the laser pointer only when you want to call attention to a specific item on a slide. Direct the laser pointer specifically at the item. And if, for example, you are showing a pathway, trace it with the pointer. If you shake during presentations, hold the laser pointer in one hand and use the other hand to steady that hand.

If the conference is in person and has a speaker ready room (a room in which speakers can test their audiovisuals), check that your slides are functioning properly. Also, if possible, get to the hall before the audience does. Make sure that the projector is working, ascertain that your slides will indeed project, and check the lights. If you will use a microphone, ensure that it is functioning.

Normally, each slide should make one simple, easily understood visual statement. The slide should supplement what you are saying when it is on the screen; it should not simply repeat what you are saying, or vice versa. Except when doing so could help overcome a language barrier, do not read the slide text to the audience.

A nice touch, and a tradition in some research areas, is to include a closing slide acknowledging your collaborators and perhaps showing a photo of the research group. If the research being reported was a team effort, consider including such a slide if appropriate in your field.

Slides that are thoughtfully designed, well prepared, and skillfully used can greatly enhance the value of a scientific presentation. Poor slides would have ruined Cicero.