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have also tried to cheaper alternative methods to making pencasts (NB: I haven't used either for a while so this may be outdated):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

Making video lectures: Powerpoint screencasts

I have previously discussed the many advantages of video lectures compared to live lectures. Here discuss how I make most of my video lectures.

Almost all my video lectures are screencasts of Powerpoint presentations made using the screencasting software Screenflow.  Screenflow only works on Macs but there is a very similar program for Windows called Camtasia.

The two videos above nicely illustrate how I do it: you simply go through your Powerpoint presentation of your computer and Screenflow records what's happening on the screen and what you say.Then, usually after a bit of editing, I upload the video to my Youtube account.



There are two main differences between the videos and my approach: One difference is that I use the earphones with microphone that came with my iPhone for a better audio recording. The other difference is that I don't record myself talking with my webcam because I personally find these "talking heads" distracting when I watch such videos.

There are other ways of recording Powerpoint presentations.  The reason I used Screenflow is that
it has very powerful, yet easy-to-use, editing capabilities for fixing mistakes. The same is true for Camtasia and this video gives an example of a correcting a mistake.




Some practical tips
* Once you start a recording, don't stop.  If you make a mistake, keep quiet for a moment and start that part over.  You can fix the mistake by editing and the quiet moment allows you to cut without interrupting the narration.

* Keep quiet for a second before and after changing slides. This allows you fix errors on a particular slide without affecting other slides.

* Once you finish recording a video your first instinct will be to delete it.  Try waiting a day and listening to it again. I bet you'll feel better about it.

* Hosting your videos on Youtube has many advantages such as optimized views for mobile devices and good buffering for slow internet connections.  You can control who can access your videos on Youtube, though there is really no good reason not to share the video with everyone.

* However, if you want to host the video in a place not recognized by Screenflow or Camtasia, such as a university server, you can export the movie to a file and upload the file.

Other uses of screencast
Screencasting in general, and Screenflow and Camtasia in particular, are very versatile tools that can be used for many other things.

For example, I frequently use Screenflow to grab fragments of Youtube videos or simulations to include in my Powerpoint slides.  Here are some examples:



A screencast is also an excellent way to show how to use a particular program or website.  Here I show how to use a particular feature of the program MAPLE.


 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

Computational Chemistry Course - Exploring a PES

I made this video to illustrate the basic ideas behind the generation of a reaction profile. I show how to "explore" the potential energy surface for a basic Diels-Alder reaction.



The small animations were produced visualizing with Molden actual calculation done with Gaussian at HF/sto-3g level and screencasted with ScrenFlow. The entire video is another ScreenFlow capture of a PowerPoint presentation with my voice over.

Computational Chemistry Course - Optimization Techniques part 3

Another video I made for the Computational Chemistry course. This is the third in the series relative to the Optimization techniques module. It is a simple presentation captured with ScreenFlow and my voice over. The water vibrational modes were computed with MolCalc, screencasted and inserted into the presentation.

Very quick introduction to molecular quantum mechanics for simple systems

a. A brief motivation for the Schrödinger equation

b. Four simple examples of the Schrödinger equation

c. Solutions to the Schrödinger equation for three simple systems

d. Changes in quantum states and spectroscopy: a simple example

e. Tunneling and scanning tunneling microscopy 

The simulations are done using a free program called Molecular Workbench.  Once you have installed Molecular Workbench you can download the list of simulations here.

Slides for video a-d

Unifying Concepts in Nanoscience video slides from molmodbasics

This work is licensed under a Creative Commons Attribution 3.0 Unported License.  

Computing molecular properties with molecular dynamics - part 2

These videos represent a lecture from my course Molecular Statistics that gives brief introduction to computing molecular properties with molecular dynamics.  The lectures are in Danish.  The lecture notes can be found here.  See also this blog post.

a. Computing molecular properties
b. Computing the free energy difference part 1
c. Computing the free energy difference part 2

Technical details
The first video was made with ScreenFlow and Molecular Workbench
The remaining videos was made with an iPad, Apple head-phones, the Explain Everything app, and a Bamboo Stylus.

A brief introduction to periodic boundary conditions (in Danish)

These videos represent a lecture from my course Molecular Statistics that gives brief introduction to periodic boundary conditions.  The lectures are in Danish.  The lecture notes can be found here.  See also this blog post.

a. The boundary problem
b. Periodic boundary conditions: a sketch
c. Periodic boundary conditions: an animation
d. Cutoffs - Part 1
e. Cutoffs - Part 2

Technical details
The first video was made with ScreenFlow and Molecular Workbench
The remaining videos was made with an iPad, Apple head-phones, the Explain Everything app, and a Bamboo Stylus.


This work is licensed under a Creative Commons Attribution 3.0 Unported License.

Brief introduction to molecular dynamics (in Danish)

These videos represent 2 lectures from my course Molecular Statistics, that gives a brief introduction to Lennard-Jones Potentials and molecular dynamics.  The lectures are in Danish.  The lecture notes can be found here.

a. Modeling gases and liquids
b. Newtons equation of motion underlies molecular dynamics-part 1
c. The Lennard-Jones Potential
d. Newtons equation of motion underlies molecular dynamics-part 2
e. Initialization
f. Computing the force and taking the step
g. The step size (The video contains a small mistake which is corrected here)
h. Equilibration and constant E vs constant T simulations

Technical details
The first video was made with ScreenFlow and Molecular Workbench
The remaining videos was made with an iPad, Apple head-phones, the Explain Everything app, and a Bamboo Stylus.


This work is licensed under a Creative Commons Attribution 3.0 Unported License.

Pen- and screencasting

Some links for todays "educational" seminar on pen- and screencasting

Tools for pencasting
The Smartpen
The Replaynote app for the iPad Limited to 10 min recordings
The Wacom Bamboo Tablet/Screenflow (Mac) or Camtasia (Windows)

Miscellaneous
Free screencasting software, limited to 15 min recordings
The Khan Academy collection of thousands of pencasts
9. klasses matematikpensum som pencasts

Uses for pencasting
Review of lectures
Supplementary lectures
Homework problems/solutions

Other uses for screencasting
Powerpoint lectures
How to use programs such as Maple
Research presentations
Summary of research papers
Animation in Powerpoint

Computational Chemistry Course - Optimization techniques introduction part 2

This is a video I made for the Computational Chemistry course. It is relative to the Optimization techniques module. It is a simple presentation captured with ScreenFlow and my voice over.

Computational Chemistry Course - Optimization techniques introduction part 1

This is a video I made for the Computational Chemistry course. It is relative to the Optimization techniques module. It is a simple presentation captured with ScreenFlow and my voice over.

Derivatives and heat capacities for a simple system

Here are three videos I made on computing the heat capacity for a simple two-state system and plotting them using either Maple or Wolfram-Alpha.  The videos are in Danish.

The pencast video was made with an iPad, the ReplayNote app and a Just Mobile AluPen.  The other two videos where made with the Screenflow screencasting software.

Computational Chemistry Course - Basis Sets introduction part 1

This is a video I made for the Computational Chemistry course. It is relative to the Basis Set module. It is a simple presentation captured with ScreenFlow and my voice over.

Using Maple for Statistical Mechanics homework

My first pencast: Partition functions and conformational probabilities of a simple polymer

Tools: A MacBook Pro, the headphones with microphone that came with my iPhone, A Wacom Bamboo Tablet, SketchBookExpress, and ScreenFlow.