Creating Short Topical Presentations

In practice, people have attention spans of 10-15min at a stretch for consuming media at the level of thought and analysis required for technical and scientific learning. Breaking up teaching sessions, adding variety to presentation formats, and changing how a subject is presented are all techniques that are scientifically demonstrated to improve learning.

For this reason, we aim to keep topical presentations to 10 to 15 minutes. If a subject absolutely requires more time than that, it should be broken up into two related presentations. Usually, though, there is a lot of time that can be trimmed out of a video presentation relative to a live classroom performance. Here are some time-saving tips:

• Avoid repetition. The viewer can always rewind.
• Pick up the pace and avoid stops. The viewer can always pause when they need to.
• Keep it punchy. Topical presentations are meant to introduce a subject and provide intuition. Printed media are more appropriate for detailed technical content that would be useful as a reference for later. Avoid incorporating too much reference material into a video.

Materials

There are many ways to do this, but I've chosen to copy what Salman Khan of Khan Academy uses:

• A Wacom Bamboo Tablet
• Quicktime Player (on my Mac)

As for video editing, there is much software out there. Chat Hull had a good time editing his video on the Radiometer Equation using MPEG Streamclip. It allowed him to easily cut/edit the video, as well as to physically crop the window and to compress the file size.

And as for video posting, unless you're lucky, you will only be able to post videos with lengths of 15 minutes or less. This is probably a good thing... To post videos, sign up on YouTube.

Topical Videos

• Salman Khan on Khan Academy: On using instructional videos instead of lecture
• How to make a Khan Academy-style video