Category Archives: Video

Optimal Length of Instructional Video

Someone recently pointed out this research to me. Prof Guo believes, based on the data collected from thousands of educational videos served on EdX, that six minutes is the optimal educational video length. People are willing to watch six minutes, but for every minute longer than that, the average number of minutes drops–drops not just as percentage, but in terms of the total number of minutes. If learners see that a video is 20 minutes long, they’ll quit well before six minutes (perhaps with good intentions of coming back later, but they don’t).

This is interesting for a lot of reasons, but one of them is that the governing body over learning for CPA firms recently gave the OK for firms to give formal credit for nano-learning. But to give credit, nano-learnings have to be at least 10 minutes long. EdX’s data* suggests that’s almost 70% too long!

*Of course, EdX’s data is not specific to adults learning in a professional setting. And naturally there are any number of factors in play that would make a three minute video seem interminable and a fifteen minute or even an hour long video fly by. But it’s still interesting stuff.

Articulate Storyline Has an Outstanding mp4 Engine

A subject matter expert handed us some screen cam videos last week to include in e-learning. The videos were high resolution–higher than could be used in the course without down-sampling them somewhat. The videos were of an Excel plug-in being used with a spreadsheet, so lots of details and tiny text.

(Lesson learned: We needed to be in on the process early enough to help the developer create screen captures to our specs. But at least down-sampling is better than up-sampling.)

As a quick experiment, the first thing we tried was loading them into a couple of video editors, resizing, and transcoding from wmv to mp4. The quality was not great and the file sizes ballooned despite our best efforts (bit rates, frames per second, etc.; Premiere overall did better than Vegas, my preferred tool.)

We inserted the videos into Storyline, resized them, cranked the video quality slider all the way to the right and crossed our fingers. I had visions of having to go back to the SMEs or having to spend lots of time cropping the videos, but Storyline did shockingly well. The quality was as good as we got with the dedicated editors, but at a fraction of the file size.


I’m not suggesting that a dedicated video pro couldn’t have done better, of course, but for almost no effort the native Storyline video renderer is quite impressive.