Last week I wrote about talk content. It’s time for round two of talk advice: delivery. These points are largely aimed at technical talks given on projected slides, since that is the overwhelming majority of the talks I’ve attended in the past ten years.

First, addressing slides or boardwork:

• Don’t put too much on a slide.
• However, don’t put so little on each slide that you’ve moved on to the next before the audience has time to read it.
• Feel free to only say some things. In fact, if literally everything is written out the audience may wonder why they’re listening to you when it would be much faster to read the slides. You need the key points, the technical definitions, and anything else the audience may want to re-read, as well as diagrams or pictures. Think of your slides as the highlighted or boxed portions of a textbook.
• It is helpful to repeat important information (especially definitions) on later slides, or at least verbally.
• Turn down the contrast and brightness on your computer screen (both separately and together) to check readability if you’re using anything other than black and white; projectors often wash things out a bit.
• In a chalkboard talk, write top to bottom, left to right, and respect the seams of the board as edges of paper – it is difficult to write across them neatly. When going back for a second round, erase your previous writing thoroughly.
• Make sure the type (or your handwriting) is large enough.
• Use whitespace generously – avoid large blocks of solid text as much as possible.
• Landscape orientation allows higher magnification since it matches the usual projection screen dimensions better than portrait.
• Stand to the side of your slides or what you’ve just written. It is continually surprising to me the number of people who stand in front of their writing until they have moved far enough past it in the talk that reading it would be a distraction to the audience instead of a help.
• Proofread! You might not catch everything, but you’ll catch the most egregious errors. Putting the slides aside for a day will help your observational abilities – when you look at something repeatedly you often start seeing your memory of it rather than the actuality.

Secondly, your speaking:

• Practice! When you have given many talks you will need less practice, but when you are starting out, multiple sessions are desirable.
• I have never attended a talk that was read aloud from a prepared paper that did not bore me to tears. Use notes, but don’t read word for word.
• Speak loudly but do not shout. While whispering and mumbling are clearly not desirable, neither is yelling. Note that you can yell without raising your voice, as well. The audience will not understand more if you are strenuously emphatic; they will simply feel accosted.
• Note that while practicing your talk by yourself is good, it is inexact for timing. Err on the side of “too short” (within reason, of course – prepare more than thirty minutes of material for an hour-long talk); between extra things you say and questions from the audience the length will most likely increase, and if not, well, no one minds ending early.