Presentations: special for students

The mistakes addressed here may happen at any level, but are very frequent in a specific case: students having to present their first research projects within their university. So I’ll write having them in mind; feel free to generalize.

Mistake 1: assume that the basics of your work are known by everyone in the audience

Let me explain this by public confession: in this very moment, I would not be able to recover from my memory such basic stuff as the equation of the incompressible fluid, the critical exponent of magnetization in the Ising model, the definition of the Young coefficient, the reaction to explain which the neutrino was first postulated… Similarly, most of my colleagues may need to be reminded that Bell’s inequalities are tests on two entangled particles, or that quantum cryptography is about Alice trying to establish a secret key with Bob while Eve tries to spy, etc.

We won’t need much to remember these things: show the equations or the schemes on a slide, spend 20-30 seconds of words, and it will come back. So, the matter is not to spend too much time recalling trivialities, just to set rapidly the stage.

Mistake 2: assume that you have show all that you have done (especially the tedious part)

Many students think that they have to impress the audience with their advanced results; or even worse, that they should show how much they have worked. The tedious part of your work must indeed be reported somewhere: in the written report that normally accompanies this kind of university projects. There, there must be lines and lines of code, of equations, of calibration procedures for your devices… But not in the oral presentation.

Why? Well, my explanation is: a reader can choose which parts of your report to read carefully and which to browse fast; but in an oral presentation, the audience cannot really choose. So, since you have only one message to convey, try not to convey your sufferings 😉

Last year we had a fantastic presentation by a student on chaos-induced tunneling (a topic in quantum chaos, of which I knew nothing before). He introduced the main ideas, then showed one (one!) graph and said “this is the spectrum for the model I have studied: this peak corresponds to this orbit, etc”. It was patent to everyone that, in order to get there, he had to write many complicated equations in a computer, then sort out the results — but he was kind enough not to bother us with all the definitions and show us directly the digested result.

As a counter-example, I remember a student who spent her presentation telling us how she wrote a code to map a database that was using x=0 or 1 onto another database that was rather using x=+1 or -1. The audience can safely assume that you have made no mistake in such technicalities. Incidentally, that student had forgotten to tell us what the information in the database was…

Mistake 3: lack of suitable citations

I have seen many presentations in which the only references given looked like: [Very famous fellow 1905], [My supervisor 2007, 2009]; the latter being the two articles, often published in minor journals, that the supervisor suggested as starting point. At the end of your project, you are supposed to know many more references, notably books and review papers.

A correct presentation has:

  1. Basic introduction, with reference: [Very famous fellow 1905]
  2. Overview of progress along the years, with reference: [Book 1960], [Recent review 1998], and maybe a couple of milestone papers
  3. Scope of my project, with reference: [My supervisor 2007, 2009] and [some other active fellow, 2008].

Mistake 4: repeat blindly what you have read

Let me explain this by two examples I witnessed:

  • Presentation on a source of entanglement by Kwiat et al. The student has read in the introduction of the paper the following motivation: “The generation of entangled photons is promising for applications, for instance in super-dense coding”. He just repeated that sentence in his presentation. I asked him what is “super-dense coding”: he had no idea!
  • Presentation on decoherence. The student writes on a slide that “typical decoherence times are 10^{-23} seconds”. I asked him what physical systems he had in mind; answer “hmmm, none specifically, this is very general”. Well, if it would be so general, we would never have observed any quantum phenomenon! That number is probably an estimate for a macroscopic system.

I like to compare this to a sentence from the 1st Letter of St Peter: “Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have” — just apply this to your presentation: be ready to explain why you are saying that!

If this last point is not clear yet, don’t worry: a new round of presentations is coming soon, I’ll surely have new examples to update you 😉


About valerio

Principal investigator at Centre for Quantum Technologies and professor at National University of Singapore

Posted on October 24, 2011, in Talks & presentations. Bookmark the permalink. Leave a comment.

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