Rainbows and refraction II

Taking the same graphics as in this post, but presenting them differently.

In the previous post, I presented a screen cast explaining, in a very text-booky way, how rainbows form. Today, I am using the same graphics, but I have broken the movie into six individual snippets.

I’m starting out from the schematic that concluded last post’s movie and ask  five questions that you could ask yourself to check whether you understand the schematic:

Ideally I want to link the other five of the movies into the one above, but I haven’t figured out how to do that yet, so here you go for the answers:

What do you think of this way of presenting the material? Do you like it better than the textbook-y movie? I’m curious to hear your opinions!

For both this and the other way of displaying the material, I am toying with the idea of adding quizzes throughout the movies, in a programmed learning kind of way. But considering all the pros and cons, I haven’t made a final decision on it yet. What do you think?

Rainbows and refraction

Why is a rainbow always red on top and blue at the bottom?

We always talk about prisms and refraction and stuff, but be honest – would you be able to explain the order of colors in a rainbow without pausing and thinking first?

Screen shot 2014-07-13 at 3.34.19 PM
Rainbow. Picture taken in Laufenselden in 1996

As I said the other day, I am currently experimenting with screen casts. This is my very first attempt – I didn’t write a script so it is pretty chaotic, I have a cold (which you can hear from my voice), my handwriting sucks, the movie is, at 4 minutes, about twice as long as I wanted it to be – it is not perfect and I will certainly modify it before using it in teaching. But I would be very interested in your feedback so I can improve it!

As you noticed, this is a very textbook-y screen cast. I’ll present an alternative model for the same topic in my next post.

P.S.: As you might have noticed from the watermarks in the video, I have continued experimenting with screen cast programs and am currently using Doceri. And I am very happy with it!

Teaching videos

Trying to figure out a technique that works for me.

I recently talked to a professor at my university who is toying with the idea of making teaching videos. As a reader of my blog you know the kind of videos I usually show here: Pretty much un-edited movies of some kind of experiment. No voice-overs, no text floating in and out, nothing to make those videos work as stand-alone teaching units. And that is how I want them for my own teaching: When I use them in class, I show them on mute, and run and pause and re-run and point and talk, all the time reacting to my students’ reactions. However, this was not how that professor wanted to use the videos in his classes. And since I was ready to try something new and had wanted to explore teaching videos for some time, here we go.

What that professor told me he wanted to do was basically have a document camera on his desk to record him drawing on a piece of paper in addition to recording his oral explanations while he is drawing. So this is the first thing I tried. For your reference I’m posting a movie below, but be warned: I stopped editing fairly early on because I realized it wasn’t working for me and I wanted to try something else.

Why was this not working for me? Well, basically because I didn’t like the camera’s weird perspective on the paper (yes, I realize I could have set up the whole thing differently!), the shadows the tripod, the camera and my hand cast on the paper, the inflexibility when I had drawn something and couldn’t change it but had to start over. Plus pausing the camera and starting up again was complicated (as in: the camera moved, there were shadows on the paper, I would have to edit the transitions). At this point I hadn’t written a script, so when I was starting to think about the voice-over, I realized that the story would be a lot easier if I drew things in a different order (for example if I drew the incoming ray, the refracted ray and only then the vertical line relative to which we measure the angles). Somehow it all felt like too much of a hassle.

So the next thing I tried was drawing on a tablet and doing a screen cast of that. Below you see my very first attempt. The clear advantage here is that I can easily pause and resume recording. While recording is paused, I can draw more or import graphics. I’m using ScreenChomp, which was the first tool I had at hand. I might still try others, but I am actually pretty happy with how easy it is to use and how well it works right away. Again, this isn’t a finished movie (I’m for example expecting my handwriting to become a lot clearer when I’m used to writing on a tablet and when I’m using a pen rather than my finger) and I am only posting to give you an idea of what you could expect using that tool.

My conclusion: A lot more promising than recording the drawing on paper! And definitely an option that I am going to explore further.

There are also screen capture tools that my university is already using in combination with lecture recordings, and I am going to find out more about how (well) they work tomorrow from my colleague Alex. [edit: Wow. There are so many different software solutions! I’ll definitely present them in more detail at some point…]

There are all kinds of theories on how to make teaching videos (for example by Derek Muller et al. (2008) who show that including misconceptions in teaching videos helps people learn better than just simply showing them a good and correct explanation) and in what didactical scenarios to use them (for example the flipped classroom scenario). And now that I am confident that the technical aspects can work without too much of a hassle, I’m ready to start working on the didactical aspects. Stay tuned!