Making a scientific oral presentation

All what follows is based on mistakes that my young colleagues make almost always!
The goal, here, is to help you avoiding them, and this is simple: yo will usimply need to
- read slowly what I am explaining
- follow the rules one by one.

Let's begin now:

1. You have to make an oral scientific presentation. Don't dive into the ppt immediately !

2. Because there is a difference to make between:
- the content of the talk (science, technology)
- the way the content is communicated.

3. And you cannot make a good communication if what you have to tell is not well defined, if the scientific/technologic content is not clear.
In other words, you CANNOT explain what you don't understand yourself.

4. This is the major mistake usually done: too many people just copy and paste information that they found, and when it is done, they don't ask themselves what it means really, so that when they are lecturing, the describe something that they don't understand.
Let's put it this way: describing something vaguely is not understanding it, and even less explaining it to others.

5. A second pitfall is when there is too much to say in too short a time: to take comparisons, don't try to put 1 L of water into 1 cm3, because it will not fit; don't try to go through the wall, because you will hurt yourself...

6. This is why a rule is  often given (I am sure that you heard it before): 20 minutes, 20 slides including the title, the table of content, and the reference list in the end.
Please, don't try to escape this rule, and do not apply it is a bad way, i.e., in putting too many things in each slide (we shall see later that each slide should contain only one title, and one graph or picture).

7. But when I say that, I am slightly misleading you, because it is in the communication domain.
 The idea is simply that, BEFOREHAND, you have to decide ONE idea that you are going to develop.
Hence a good advice: why wouldn't you simply ask ONE question ?  (for example: how to increase the viscosity of oil using polyphenols (answer: make a gel)? Or why does stale bread soften when heated in an oven (glassy state, crystallization, ...)  And your talk would be organized around answering this question.

8. By the way,  a good advice is to make the oral presentation using FIRST a doc file, with 20 lines (numbered 1 to 20): you write in each what will be the content of the slide (and this will make the title of the slide).
I show how it has to be done :

 

Slide
Content
 

 1
titre of the presensation, logos, authors, date
 

 2
table of content : tell how the question will be discussed
 

 3
The question given (if it is not the title of the ppt), or explained
 4

 5

 6

 7

 8

 9

 10

 11

 12

13

14

15

16

17

18

19
Conclusions and perspectives :
1. for conclusions, very few, but strong ; it can be the answer to the question given in the introduction, the most important ideas/concepts to remember
2. Prefer Perspectives to  conclusions: you have to open, not to close !
And please, no "thank you for your attention" (they were sleeping and you will make them uncomfortable)
 

20
References : please be sure that you give only good references !
In the alphabetical order
And of course all with the same format :
Author I. Year. Title of the paper, Title of the journal, 5(2), 23-29.

9. Now, of course, in a scientific presentation, one has to explain results only for experiments that are given before, for example. In other words, nobody can understand results of an experiment that is not given.

10. Keep in mind the simple presentation:
- one (structuring) question
- the context : why it is interesting to consider this question; here you will probably have to explain what are the objects that you are discussing (for example, if you speak of gels, why not giving the IUPAC definition of a gel? of if you speak of surface tension, give the definition very clearly... to the others and to yourself)
- how it was studied experimentally (the general strategy of the study)
- the Materials and Methods (the detailed experiments)
- the results
- the discussion of the results

11. Now, also positively, a good advice : don't try to be too general at the beginning, because your audience will not understand anything. Begin with one  good example, and give the generalities later.
For example, if you have to deal with surface tension, take the example of a board (area A) at the surface on a liquide (viscosity η) of thickness e, with an applied force F.

12. Be quantitative, fix ideas with equations and numerical applications (the equivalent of small exercises to test the theoretical knowledge after learning a general important law; e.g. calculating the force needed to move a board 1 m2 at the surface of water, by 1 m in 1 s).
And remember that in science, adjectives and adverbs are "forbidden": they should be replaced by the answer to the question "how much?"

13. Start from the known before moving toward the unknown: remember that discovering a new field of knowledge (your audience) is like discovering a new country: you have to follow a way (or road, lane...) without jumps. In other words, you and your audience will have to make all steps (I mean, putting one foot in front of the other and again).
 
14. Let's now move to the communication part.
Please DO NOT use the templates given by the ppt software, because they are pushing you to the mistake, containing unsignificant objects, such as colored bars that prevent you to put the references at the bottom, large colored area that takes space that you need for your own content !
For each slide, make simply:
- one title (at the top of the slides, always in the same position, at the left or at the center)
- one picture (photo, graph, equation, sequence of equations...)
- a reference in small letters at the bottem of the slide, in small size, either in full or abbreviated  (in this second case, write simply "Author, year", or "Author1 and Author2, year", or "Author1 et al., year").

15. About the characters : please, only one type (font) ! And only two sizes: one for the title of the slide, and one for comments.

16. NEVER write sentences that you would have to say (your audience will try to read it, and when they read, they will not be able to hear you).
If you really need to have text that can help you to present orally, put it in the "comments" part below (not displayed)... but then, no full sentences, only keywords to guide you.

17. Of course, the graph should have the axes given: what it is, units, etc.
The size of the objects that you describe has to be given, and, more generally, numerical information can be given (for example, in a microscopic picture).
Don't add a caption since it  should be the title of the slide (only the reference from the graph/picture is compulsory).

18. If you take a picture from someone (and you have to), it should:
- be from a good paper (please see "How to recognize bad from good papers")
- be along with a credit ("From Author, year", if it was modified, or simply "Author, year" if it unchanged).

19. In order to make the discussion/questions easier,  number the slides at the bottom right...

20. Because remember (and apply) this rule: everybody reads from left to right, and from top to bottom.

21. Don't forget to always show the chemical formulas of compounds of which you say the name (and discuss the reactivity of the compounds)

22. For definitions, use always the internationally accepted one (or say that this is very idiosyncratic from the author of an article that you quote).

23. The next seems a detail, but it is indeed very important, because one recognizes the scientific quality after details: remember that oils and fats are not made of fatty acids, but of triglycerides; and proteins are not made of amino acids, but of aminoacid residues; don't speak of glucose, but of D-glucose ; and when you draw chemical formula, use always the same representation.

24. Be sure that your audience knows enough mathematics: gradient, for example. Don't hesitate to explain them.

25. No vague sketch when discussing chemistry: we need the exact object, with all atoms (except perhaps some H), so that we can see the electrons in excess).

26. References should ALWAYS be  good ones. And from scientific journals, not popularization internet sites, for example. And figures as well.

27. Details about layout :
- Spelling !
- Alignments
- Turning spaces (the same space around an object such a a logo in a corner)
- remember the 2/3-1/3 rule : twice the space over a title than between the title and the text to which it corresponds
- make a pdf and not only ppt, because in the past, there were problems.

28. When showing the slides, don't move your hands erratically. Instead put your fingers  on each object that you are describing verbally. Yes, touch the board, putting your finger on each object that you discuss (and please don't move it while you remain on the same object; also if using a pointer, avoid absolutely moving it around, swirling! You can also hold a pen, for example, in order to avoid making unsignificant gestures).

29. Be SLOW, and even better, be EVEN SLOWER than slow.
Nothing worse than people saying very difficult expressions ( > 3 syllabes) such as "complexe polydispersed interconnected moving systems" : you can say that at ordinary speech velocity... but it will take dozens of seconds before your audience can understand what it means: they will have to translate slowly, in their mind, what it means... so that they are lost because you moved in the meantime.
I insist: don't speak too fast : remember that we are all slow minds,  and it is useless to make fast speech that nobody understand.
And I insist again : go SLOWLY: remember that clarity (i.e. being able to understand, on the other side) is the politeness of who speaks in front of an audience ; be polite !

30. And this leads me to this main advice: remember the "being clear is the POLITENESS that you should have when you speak in front of an audience".

31. I insist: you don't speak to yourself, but to others.  We don't care that you speak; on the other hand, the main point is that THEY HAVE to understand... otherwise your speech is a failure. Assume the audience knows nothing about the topic.

32. In view of being clear, explain slowly all what we see in the figures.

33. I was ready to write "Don't read text on the slides: comment it, explain it"... but if you applied one of the above rules, there is nothing to read !

34. In the slide, but also in your speech, chase adverbs and adjectives because this is unscientific: instead, answer to the question "how much"

35. Finally, remember that your duty is to make your friends happy, not boring. If you are positively interested in what you show, it's better.