Recording Computer Science Lectures

I don’t lecture. At least not in the traditional sage on the stage sense. I semi jokingly tell my students on the first day that going over the syllabus is the only time that I’m going to stand at the front of the room without giving them something to do while I talk.

But we do have to cover new material. So what I do is project my screen and then share it in Adobe Connect. Some students like to watch the projector screen. But most open Connect on one side of their monitor and their editor on the other and follow along with me coding. It’s fun when an administrator walks through and sees me walking around talking to the students’ backs. But it’s all good once they realize students are watching on their own screens.

So when we do a new topic, last week it was Strings, I do a demo in NetBeans and the students follow along. 

Posting the Lesson

Students have trouble keeping up. Some prefer to just listen. Files get lost. So I’ve always had some way of posting what we did in class where they could get to it later.

My current solution is to create a GitHub Gist of the code that we typed during class and then post it in a Canvas discussion. I tried using Slack this year, but it just didn’t work well for me.

And that works okay as a backup. But code without context is tough for rookie coders.

Screen Casts

The first step was getting a recording of what’s on the projector.

I’ve used a program called OBS Studio to create YouTube videos for a summer project.  OBS makes it very easy to do screen casts and save the recordings, although it did take a little tweaking of the settings to get it working like I wanted it to.

Last year I tried this after a student asked if I could record my lessons. It was a really great idea so I brought up a cheap computer microphone from home and gave it a shot.  The recording was okay, but I couldn’t teach that way. I walk around way too much in class to be stuck behind my desk so that the microphone could pick up my voice.

Wireless Mic

Getting a wireless microphone was the fix.  I bought the Samson XPD1.

I didn’t do much research. This was one of the first that came up when I was searching. There’s a USB receiver that pairs with the belt pack which seemed like a better idea than using something with set channel numbers.

It was easy enough to set the wireless mic as the default audio input in OBS. So now when I do demos I have my demo setup on the monitor that’s synced to my projector and OBS and Adobe Connect running on the other so that I can control them.

What I’ve found is that now that I’m used to recording myself, and have gotten over that weird feeling listening to my own voice, I’m recording pretty much everything. The plan was originally to record demos which tend to be about 20 or 25 minutes long. But I’ve started recording myself when we go over warm ups which is rarely more than a 2 minute video.

The only thing that I was disappointed in when I got the microphone was that it didn’t have a mute button. But it connects to the receiver so quickly that I can just turn off the belt pack, sneeze, and then turn it back on.

Publishing the Video

Between classes I upload the videos to my classroom YouTube channel. I keep them unlisted so that they’re not fully public but can still be linked to and embedded into other web sites.

And then I’ll take the Gist that I created from the demo along with the videos and embed them into a discussion post in Canvas.

I do record every class, even though the demo is pretty much the same. Sometimes I’ll realize that I don’t do very well in one class and then I won’t publish that video. Sometimes other things, like fire drills, keep one of the videos from not working.

Classroom Effects?

It’s tough to compare one year to previous years. But it does seem like there are fewer questions on things that we went over in demos.

The only negative that I’ve come across so far is that when students ask questions they’re not picked up by the microphone. Although, I think I actually prefer it that way. It keeps them from having to worry about being recorded. I think the classroom environment might be different if it wasn’t just the screen and my voice on the recordings. Some students really wouldn’t want their voice on the recording. So I usually just repeat the question. And even without the recording that helps the students who may have missed the question originally.

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