Thursday, July 24, 2014

Making video lectures: pencasts

The above video shows a pencast - i.e. a video lecture mimicking a blackboard lecture (it's in Danish but you get the idea).  This is an alternative to the Powerpoint based video lectures that I wrote about here.

The iPad + Explain Everything app
The pencast is made using an iPad and a $3 app called Explain Everything. In addition I used the headphones/microphone that came with my iPhone (which makes the audio recording a bit better) and a stylus.  Using a good stylus is really key to this approach and I have good experiences with both the Jot Script and the Jot Pro (I can't quite make up my mind whether the Script was wort the extra money).

There are many other pencasts apps for the iPad but all the other ones I have seen only give you one finite size page, whereas Explain Everhing gives you unlimited number of pages of infinite size (see 2:20 min of the video immediately above.  The video at the top of this post uses one infinite size page.

While I usually upload the video to Youtube directly from the app, it is also possible to save the movie file on Dropbox and import it into a video editing program such as Screenflow to edit out mistakes.

Note that you can import pictures, pdf files, and even entire powerpoint presentations into Explain everything to use as part of your pencasts

Other ways of making pencasts
While the Explain Everything app is cheap investing in an iPad just to make screencasts is relatively expensive.  I have also tried to cheaper alternative methods to making pencasts (NB: I haven't used either for a while so this may be outdated):

The Echo Smart Pen.  The main advantage of this pen is that it is an actual pen writing on real paper so the writing process will seem more natural.  Another advantage is that it produces an animated pdf file that makes it easy to skip or fast forward through the presentation.

The disadvantages are that (1) I found the file management (transfer, upload, etc) very cumbersome and non-intuitive, (2) no way to edit out mistakes (3) no way to import pictures or files, and (4) only one color.

Graphics tablet & pen. In this approach, made famous of Salman Khan, you use such a tablet to write in a graphics program (I used this one) on your computer while recording using screencasting software.  While low-end tablets are much cheaper than the iPad, it is much harder to learn to write one place (the tablet) while the text appears another place (the computer screen).  I, for one, quickly gave up.

Powerpoint or pencast presentation (repeated from this post):
For live lecturing students tend to favor chalk-board lectures over Powerpoint lectures, because the pace of chalk-board lectures tends to match that of note-taking.  The relatively slower pace of chalk-board lecturing also means that fewer new concepts are introduced during lecture.

In the case of video lectures these differences largely disappear.  Students can pause and repeat Powerpoint video lectures. Pen-cast lectures (the video equivalent of chalk-board lectures) are no longer restrained by the available lecture time and can cover just as much as Powerpoint lectures.

It it telling that it is possible to view Powerpoint video lectures on the on-line platform Coursera at 1.5 or 2 times the regular speed. There seems to be no demand for slowing the Powerpoint lectures down!

I tend to make Powerpoint video lectures rather than pen-casts because I often present rather complicated equations or diagrams that are laborious to write or sketch by hand. However, if I want to demonstrate some thought process (e.g. solving a problem) then I use pen-casts.

In any case, I always give students access to the Powerpoint slides or the handwritten notes I base the video on. It is much faster to read these notes than to watch the video. If the written material is clear, there is no need to view the video.

Good video lectures
* The optimal length is about 7 minutes
* One specific topic per video
* At least one multiple choice question per video
* Students can handle no more than 7 such videos (new topics) per lecture period.

This post is part of an ongoing series of post on teaching tools and tips collected here

This work is licensed under a Creative Commons Attribution 4.0

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