A colleague of mine at another university is teaching a course that he has taught before, but not recently. This is the first time he has taught this particular course in the PowerPoint Era. I have taught this course more recently and more often, so he asked me if I would be willing to send him all of my class materials for this course. Converting an entire course to a new format is a huge amount of work -- almost as much work as teaching the course for the first time, especially if you haven't taught the course in a long time.
I was happy to help my friend, and I sent him all my course materials. (Long-time readers of this blog may recall a previous mention of my friend/colleague who was a - in fact, the - bridesmaid at my wedding -- this is the same guy). Other colleagues and I who teach this same introductory level course also share course materials with each other. For this particular course, I have shared course material with ~ 7-8 colleagues in my own department and beyond.
Helping each other in this way isn't (necessarily) being lazy; it's a great way to get new images and ideas. Last year, an assistant professor and I shared course materials for the same course, and this worked out well for both of us. He was teaching the course for the first time and I was teaching it for the millionth time, but we have different fields of expertise and so each had zippy images and ideas for different parts of the course.
Similarly, I hope the friend to whom I just sent my course materials will in turn send his revised versions back to me for when I teach the course next year. There are some topics on which he is more expert than I am, and I am looking forward to seeing what he adds or improves for those topics.
Although my presentations get better with time owing to their being rejuvenated by new material obtained by this sharing, there will never be a time when I have the perfect set of prepared presentations for this class. The great thing about Science is that there is always something new and interesting to talk about -- and to figure out how to teach -- so the course material is always changing.
6 years ago