Sunday, November 30, 2008

Words of advice about giving talks

I know that there are many many resources out there on the web about how to give scientific talks (see here (pdf), here, here, and here, for example). Still, I have a few pointers to suggest, based on some recent talks that I've seen.
  • Know your audience. If you're giving a seminar, remember that you need to give an introduction that is appropriate for first-year graduate students. If you're giving a colloquium, remember that you're facing a diverse crowd that could include (in a physics department) astrophysicists, biophysicists, high energy physicists, etc., as well as their graduate students. Pitch your talk appropriately. This is (at least) doubly important if you're giving a job talk, and as my postdoctoral mentor used to point out, every talk you give is potentially a job talk.
  • Know your time constraints. Don't bring 140 slides for a 50 minute talk, and don't go way over the allotted time. In fact, for an hour talk slot I'd say aim for 50 minutes.
  • Avoid jargon; if acronyms are necessary, define them. Just because an acronym or term may be common in your sub-field, don't assume that everyone knows it. Just like most condensed matter people don't know what pseudorapidity means to a high energy physicist, most high energy physicists don't know what ARPES or XAFS are.
  • Minimize equations, even if (especially if) you're a theorist. You can always have a backup slide with enough math on it to make people's eyes bleed, if you want. For a main slide in a talk, no one (not even the experts) are going to get much out of a ton of equations. If you have to have equations, have a physical interpretation for them.
  • Don't show big scanned text passages from papers. No one is going to read them.
  • Explain the big picture. Why is this work interesting? You'd better have an answer that will be intelligible to a non-specialist. Even better, think about how you would explain your work and the point behind it to a sophomore.
  • If you're giving a ten-minute talk, don't spend two minutes showing and explaining an outline.
  • Avoid technology party fouls. Make sure that your technology works. Make sure that your fonts are readable and correct. Too many colors, too much animation, too many cutesy transitions - all of these things are distracting.
  • Make sure to repeat a question back to the questioner. This helps everyone - the semisleeping audience gets to hear what was asked, and you get to make sure that you're actually understanding the question correctly. No one wins when the speaker and questioner are talking at cross-purposes.
Feel free to add your own recommendations or warnings in the comments.


Wally.Paxton said...

Really great post. I was surprised to find in grad school how much of science is actually communication either in papers or presentations. All the great work we do is in vain if we can't communicate it effectively and get others excited about what we are doing.

Here are some additional thoughts

1. I had a recruiter tell me that the most critical slides are the first few, because that's when you make your first impression. The slides and your presentation of them should be meticulously PERFECT.

2. To many words on a slide (even if they are your own words) will have your audience reading instead of listening to what you are saying. Use key words and phrases rather than complete sentences.

3. Completely non-technical, but I think very important: Find out what your nervous ticks are and avoid them. The best way to do this is to record and review one or two of your presentations. If you do this, distracting habits are painfully obvious, for example:

"You know..."
"like, uh"
(persistent throat clearing)
(excessive use of a favorite idiom)

Anonymous said...

Interesting how most of your points seem to be a response to a particularly bad talk from last week. I wasn't impressed, either.

Douglas Natelson said...

This post wasn't a knock on a particular talk. Each point pretty much comes from a memory of a different talk, actually.

NONE said...

never ever go over the time limit. For an hour-long talk, try to finish at 50 minutes, 55 tops and leave enough room for questions.

Most people learn absolutely nothing new from most talks. By talking about the big picture - both at the beginning and in the end, you could leave people with a feeling they accomplished something by learning the big picture, even if they didn't get the technical mumbo-jumbo.

If your talk does only one thing, it should be to answer the question: "Why bother?" "Who cares?" "Why is this important?"

Surprisingly enough, even the specialists are not likely to be offended if you explained things in a simple way, as if you are talking to your grandma.

You have seen that plot a thousand times, but audience hasn't. Explain axis, legend, what is theory and what is data, what is unexpected etc.

Don't mumble, be monotonous and maintain eye contact. Wave your arms and jump up and down if that's what it takes.

Don't read off of your slides. Don't spend too much time looking at the slides - you know what's there.

No equations/formulas. Ok maybe one equation but no real math. In slides use pictures with few words - make people listen, not read.

Anonymous said...

It still amazes me how senior scientists who have given a bazillion talks and are explicitly asked ahead of time to speak for 50 minutes, will go on for an hour and fifteen minutes, sometimes putting the host in the awkward position of actually having to stop them, just as they announce to be about to start with the "last part of the talk"...

Veronica Daugherty said...

This post and the associated comments are incredibly useful to me. I had actually wandered over here to your blog because I am preparing a speech. I was interested in adding some of your thoughts about the future prospects of organic electroninc devices. I'm just a first year college student, and I've never given a scientific talk before. Thanks for the pointers!

NONE said...

As if on cure, December issue of Physics today features an article everyone must read:

Who is listening? What do they hear? - Physics Today December 2008

In communicating our science, have we put too much emphasis on the information we want to convey? Perhaps there is another way to think about it.

madraskaari said...

This is the bestest tip:

Make sure to repeat a question back to the questioner. This helps everyone - the semisleeping audience gets to hear what was asked, and you get to make sure that you're actually understanding the question correctly.

Anonymous said...

i wish i would've known the previous stuff before, especially about the ARPES and XAFS. i used those in a talk i gave for a condensed matter class and oye...

i forgot noncondensed matter people were taking the class as well.

Jackson said...

Thank you..