Friday, July 23, 2010

"I Understood Your Talk"

Often, after I give a talk, the feedback I hear back is "I understood your whole talk," or something near that.  I take it as a compliment (although I don't think it's always meant that way).

When I present a talk to systems people, I think the statement is actually meant in gratitude.  Instead of trying to force some challenging theoretical method or computation on them in the space of an hour, I've tried to give the high-level overview of what we've done (and why), and provide some simple and understandable examples behind the work that went into it.  With any luck, there's an idea or technique in there they can use themselves sometime.  I have some suspicion that many of them have suffered through a fair number of theoretical talks that have left them behind, and were grateful not to have to sit through one of those.  Also, in my experience when systems people say they don't understand a systems talk that's a bad thing;  in that case, it's often that there are some significant nagging details that haven't been discussed sufficiently that are making the listener suspicious that there's some flaw or an important side case that hasn't been adequately addressed. 

When I present a talk to theory people, it's not always clear to me how to take that comment.  There's certainly a subculture in theory CS that seems to think it's important to show how complex your result is (or, perhaps, how smart you are), never mind the audience.  On the other hand, some theory results are so complicated it is truly a challenge to try to present a lucid 1-hour talk.  In some cases, people saying they understand the talk feels like a real compliment -- thank you for presenting things in an understandable way.  In some cases, it feels like a backhanded compliment -- if it's that easy to explain, you're not working on very hard stuff, are you?  When people say after a talk they didn't understand it, it's more ambiguous -- did the speaker do a bad job, or is this really exciting new difficult stuff that will take some time to learn?

Generally, when I plan my talks, the aim is to make almost all of it understandable to as large an audience as possible.  For specialized audiences, I'm happy to go into details, but for more general audiences -- the very large bulk of my talks -- I'll aim for simple when I can.  


Rob1606 said...

Did you ever have people say to you they did not understand your talk? I would find this terrible to hear; to me, there would be nothing ambiguous about it, it was a bad talk...

I strive for these "I understood your talk" comments. I guess I used to try and impress the audience with my proofs. Now, I just try to impress them with a talk they can all follow :-)

Jico said...

I like Einstens' quote of "If you can't explain it to a six year old, you don't understand it yourself." So I agree that should be a compliment.

Michael Mitzenmacher said...

Rob -- While politeness prevents people from saying, "Your talk was incomprehensible", it's not uncommon in some talks (particularly in theory) to hear "I understood the first half, but started losing you at this proof..." As I said, some presenters view this as a goal -- only some of their audience should get everything. There are arguments why this is an appropriate style, depending on your goals.

Geoff Knauth said...

There are probably as many responses as listeners.

"I fell asleep."
"Is that all there is?"
"My brain shut down halfway."
"My brain overloaded and now I have a headache."
"I never heard that before."
"You got me thinking."
"I can't stop pondering your ideas."
"I want to investigate your ideas and write a paper."
"Russell Crowe wants to play you in a movie."
"God is holding on line 1."

Anonymous said...

The "I understood your talk" comment is good so long as it is not accompanied by "but you don't"...

Anonymous said...

Oops, I have had occasion more than once to tell a speaker "I understood your whole talk", and it never occurred to me that the speaker may think it as anything other than what I meant - a real compliment. I'm in theory, and have sat through so many talks where I got less than expected out of them, that a "understood it all" is great. If I understood it only because it was easy, I don't bother to tell the speaker anything. It's a compliment, Michael, I'm sure.

David said...

I frequently say [to myself, even] that it is the responsibility of the communicator to ensure that they are understood by the communicatee. Anything less is a communication failure, and concomitantly an intellectual failure.

Anonymous said...

I had the same thing said to me by a journal reviewer. "I understood your paper completely". Therefore, there is no contribution. Reject!

Cara said...

I too have always taken "I understood your talk" as a positive comment. I make it a goal when I prepare a talk to present complicated material in a way that can be understood by my audience, and when I achieve that, it is very satisfying. I wish more speakers would strive to have understandable talks. I'm not sure anyone appreciates a talk they can't understand, and yet, we get so many of them.