Advice on giving talks

We are at ISIT and I realize I am going over the same points multiple times with my students, so I thought of summarizing everything here.

How to give a better ISIT Talk.

1. Take your talks very seriously.

Do practice runs. Many of them. Your only hope for academia is by giving great talks. Give a practice talk to your friends. In the middle of your talk pause and quiz them: ok, did you get why alpha and beta are not independent? (hint: they did not).
If they did not, it is your problem not their problem.

2. They do not remember what alpha is.

In most talks, your audience does not understand what the notation is, what the problem is, or why they should care. Think of yourself: how often do you sleep or suffer through talks without even knowing what the problem is?
Do not treat your audience like that.

It is a typical scene when the presenter is focusing on a minor technical issue for ten minutes when 90% of the audience does not even know what exactly the problem is, or care.

One important exception is when your audience works on the same problem. Typically only a small part of your talk should be focused on these experts (see also 13).

3. Do a multi-resolution talk.

A useful guideline is: for an 18 minute talk, 7-9 minutes should go on explaining the formulation of your problem and why should anybody care. 5-6 minutes on explaining *what* the solution is and 4 minutes or so, on the actual painful technical stuff. The first part should be aimed at a first year grad student level. The second at a senior grad student in the general ISIT area and the last part to the expert working on related problems. If fewer than 90% of your audience are checking email in the last part of your talk, consider that a success.

4. Try to make things simple, not difficult.

It is a common mistake for starting grad students to think that their work is too simple. For that reason they will not mention known things (like explaining that ML decoding for the erasure channel consists of solving linear equations, because they fear this is too simple and well known).
Always mention the basic foundations while you try to explain something non-trivial. Your goal is not to sound smart but rather to have your audience walk out knowing something more.

Even when your audience hears things they already know, they get a warm fuzzy feeling, they do not think you are dumb.

5. Add redundancy, repeat a lot in words.

Do not say ‘We try to minimize d(k)’.
Say `we try to minimize the degree d which as I mentioned, is a function of the number of symbols k’. Repeat things all the time: Summarize what you will talk about, and in conclusions say the main points again.

6. Go back to basic concepts in words, repeat definitions.

Try to mention the basic mathematical components not the jargon you have introduced. Do not not say ‘Therefore, the code is MSR-optimal‘ but ‘Therefore, the code minimizes the repair communication (what we call MSR optimal)‘. Try to reduce your statements back to fundamental things like probabilities, graphs, rank of matrices, etc whenever possible. Do not just define some alpha jargon in the first slide and talk about that damn alpha throughout your talk.

7. Never go over time.

I have often seen even experienced speakers getting a warning that they have 3 minutes and still trying to go through their ten last slides. When you are running out of time, the goal is not to talk faster.

Say something like ‘Unfortunately or fortunately for you, I do not have time to go into the proof so I will have to skip it. The main ingredient involves analyzing random matchings which is done through Hall’s theorem and union bounds. Please talk to me offline if you are interested…
Then, go through your conclusions slowly, repeating your main points.
This is another example of multi-resolution: you explain the techniques at a high level first. Even if you had time, you would still first have to give a one sentence high level description and then get into the the details.

8. Draw attention to important slides.

People are probably checking the Euro final when you are at slide 4, explaining what your problem is all about. Wake them up and give a notification that this is the one slide they do not want to miss. Do this right before the critical points.

9. Every slide should have one simple message.

After you make your slides ask yourself: what is the goal of this slide, I just want to explain this part. Iteratively try to simplify your slides into smaller and smaller messages. It is easier for your audience to grasp one packet of information at a time. Do not have derivations on slides (especially for an 18 minute talk), unless there is one very simple trick you really want to show. Showing math does not make you look smarter.

10. Be minimalist.

Every word on your slides, every symbol or equation you put up there dilutes the attention of your audience. Look at each bullet/slide and ask, do I really need this part or can I remove it?

11. Be excited.

Vary the tone of your voice, it may wake up somebody. You need to entertain and perform. Think: if you are not excited with your results why should anybody else be?

12. Cite people.

When somebody has related prior work, cite them on your slide. That has the benefit of waking them up when they see or hear their name.

As Rota says: `Everyone in the audience has come to listen to your lecture with the secret hope of hearing their work mentioned.

13. Connect to what your audience cares about.

This is non-trivial and requires experience. If you are giving a talk in a fountain codes session, you do not have to spend ten minutes defining things your audience knows already. Still define it quickly to make sure everybody is on the same page on notation. Knowing how to be at the right resolution for your audience becomes easier in time.

14. Prepare your logistics.

Know the room (go there before), know who your session chair is, have your macbook projector dongle, pre-load your slides on a USB. Bring your charger, disconnect from the internet (fun Skype messages pop-up during talks). If you are using a different machine, test your Powerpoint slides (hint: they look completely different).

15. Talk to people afterwards.

Talk to people about their work and your work. Remember that this is a professional networking event. Do not hang out with your friends, you have plenty of time for that after you go back home. Networking with other students and faculty is very important, in my case I learn more by talking to people offline than in talks.

16. Engineering theory is essentially story-telling.

Our papers and talks are essentially story-telling: Here is a model for a wireless channel, here is a proof about this model. A good story has an intellectual message that will hopefully help people think about a real engineering problem in a cleaner way.
The other aspect of our job is creating algorithms that are hopefully useful in real systems. Think: what is your story and how will you present it in your talk.

17. Read the brilliant Ten Lessons I Wish I Had Been Taught by Gian-Carlo Rota.


2 thoughts on “Advice on giving talks

  1. These are great tips, and applicable to essentially any field in science! Thanks so much for posting these—they’ll be useful to my own students as well.

    One minor but important tip useful to rookie presenters: Be sure to never, EVER leave the laser pointer on as you rotate toward your audience. I’ve seen some postdocs at ACS meetings nearly blind huge swaths of the audience through a combination of lead thumbs and a tendency to rotate toward the audience while speaking.

  2. Pingback: More advice on giving talks « An Ergodic Walk

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