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September 30, 2004

Overhead Projectors and 20-Minute Technical Presentations

I listened to three 20-minute student presentations of economic research recently, and noticed something all three had in common: Each would have been better if the overhead projector had been destroyed and the student had just written on the blackboard instead.

The problem was that the speakers threw up numerous detailed slides that were too complicated to have any meaning to the audience. and without putting the notation on the board. Having to write things down would have slowed them down enough that the audience could have followed them. Also, the mathematical notation could have been up on the board for the audience to see, and they could have studied equations for more than the few seconds they are up on a screen.

It's interesting that for a short talk overhead slides are such a trap for the novice speaker. For the experienced speaker, overheads are all the more important if a talk is short, because he can save time otherwise spent writing on the board. The experienced speaker does not need the discipline of being limited to just a few equations by his writing speed.

I should note, too, that this problem is not limited to theory papers. Empirical papers are subject to it too, because the student is tempted to post too many numbers, showing too many of his different specifications. In twenty minutes, one regression equation is plenty! (combined, of course, with detailed discussion of its meaning)

Posted by erasmuse at September 30, 2004 11:14 AM

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I coach people for effective presentations, and one thing I have found that helps these novices is at least to give the audience a print-out of the Power Point slides and any other notes.

Of course, with more experience they learn to edit the presentation, slow down, don't read the slides, etc...

Posted by: bc at September 30, 2004 04:49 PM

I agree, and I would go further and apply this to beginning teachers of economics as well. I am a third year doctoral student in economics, and have taught for four semesters in a row. And what I've noticed with myself is that because I don't really know how to use slides effectively (and because I am still trying to gain mastery even of the most basics of macroeconomics to teach it effectively), the slides are not helpful. Plus, I by nature talk very fast. So taken together, I feel like the slides confuse the kids rather than help them. The only time they are helpful is when I want to show them something visual like the unemployment rate over the 20th century, or inflation, or whatever. Then, it's nice. But forcing myself to write everything on the board, while not as clean as it could be, at least slows me down, forces me to walk through each thing carefully, and I think helps students too.

I love this blog, incidentally.

Posted by: scott cunningham at October 1, 2004 06:57 AM

Thanks for the encouragement, Scott.

I should have linked to my "Aphorisms on Writing, Speaking, and Listening", which will be of interest to anyone who reads this post:


Posted by: Eric Rasmusen at October 2, 2004 04:33 PM

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