Why podcasts are not nearly as good as screencasts in science and math
So podcasting seems to be all the rage in higher education. First it started with a few schools just broadcasting information items, but then schools such as UC-Berkeley, Stanford, and MIT started posting actual class lectures for the world to listen too.
Cool, now anyone can listen to the lecture of world-renown professors on all sorts of topics. In some classes, say philosophy or political science, that’s cool. But for a hard science such as chemistry it’s tough. And as far a useful tool for students, it falls down pretty hard. Don’t get me wrong, podcasting is better than nothing, but it has some serious drawbacks.
Podcasting weaknesses:
1. Audio (only) recordings of lectures. Students today are visual learners. They watch days worth of TV each week. Their eyes seem to receive more that their ears.
2. Whole lectures (55, 90, 120 min) make for large file sizes. These are huge files for students to download, and they might not even want the whole lecture.
3. The audio file contains pauses, breaks, discussions. When reviewing the material, the student does not want to listen to the dead air in every lecture. The time students are given to write information down, class discussions, question/answer periods drag the time out.
4. Difficult for students to find ‘right’ spot in the lecture. When students go back to the podcast for reviewing and just want to listen to the 10 minute section on a specific small topic, they have to hunt and peck for it, which gets frustrating for them.
5. Attention span of students less than 10 minutes Many studies have shown that students start to tune out of lecture after as little as a few minutes with all but teh most engaging instructor. 50 minutes lecture are a lot to slog through for an MTV generation student.
What I have begun doing is what I call ’screencasts’ (aka vcasts or vodcasts) which I content are better than podcasts for a few big reasons:
Screencasting strengths:
1. Audio and video recording of lectures ‘pieces’. I visually record myself stepping through my PowerPoint slides laying down an audio track on top. I use the same words, and examples as in lecture.
2. Files available to anyone on the planet who wants to watch and listen. Two words: Open Source
3. Short lecture segments (5-15 minutes) that cover 1~2 specific topics. These are recorded in my office (or at home) on my time and are broken up into logical pieces, containing only 1 or 2 topics. This plays in nicely to the attention span of the students
4. Recorded at ‘full speed’. There are no breaks, since I am alone talking to the computer when they are recorded. I get through the material in about 40% of the time compared toa standard lecture presentation.
5. Video gives visual reference. Students can easily follow along and see where I am at in the discussion.
6. When reviewing, students quickly find the part they are looking for. Since the files are posted and recorded by individual topic, finding the one they want to view is easy.
7. No need for expensive software or large server space. I address this elsewhere.
8. Screencasts transcend semesters. I will always teach about electroneagtivity, so I can use that screencast for multiple semesters, whereas I would have to re-record lectures each semester so as not to confuse my students.
Podcasting is new and exciting yes, but it seems like we need to take one more logical step and give our students a really powerful educational tool.
The future is also bright, with online education, distance learning, textbooks becoming moot, etc. I am just glad I am still young so I can enjoy this for a while.