It might seem kind of strange that I am still thinking so much about teaching, just as the semester has ended. However, I am still working with students who had medical/family emergencies and have to make up some assignments, labs, and exams, so the semester isn't completely over. In addition, grad/undergrad research advising doesn't end with the school year, and I am also working on some of the teaching modules that I help prepare as part of a group working on science education issues. I enjoy creating these teaching modules and sharing my ideas and knowledge about interesting science topics. It's the same stuff that I use in my own teaching, but knowing that these materials (text, images, exercises) will be available to the world can be daunting. Everything in these modules has to be absolutely clear and self-contained.
When I have participated in workshops in which I've presented my teaching materials to other professors, I am often aware that some teaching methods and materials aren't easily transferred to others. To teach well, you have to be very comfortable with the subject material, and ideally have deeper knowledge than what you are presenting in class. It's best if some of this knowledge comes from experience, though of course we can't have that type of knowledge about all the concepts we teach. Some of that kind of knowledge and experience takes time to acquire, but even for early-career teachers, being confident (but not over-confident..) and caring about what you teach can go a long way. I have one colleague who cares a lot about teaching but who lacks confidence; 'good' students appreciate her efforts and her caring, and 'struggling' students can be very savage about her lack of confidence, and that can undermine her confidence further, making it harder to acquire what she needs to progress as an effective teacher.
I know several professors in my field who are outstanding teachers now but who were really awful teachers when they first started, so there is hope. These professors knew they were awful and they didn't want to be, and they eventually figured out how to do better, and even to excel. Now it's hard to imagine that they were ever awful teachers. I know a few professors who teach a limited amount because they are terrible teachers. Is there nothing to be done to help them improve, or are the required changes in personality and teaching methods too drastic?
It's not easy to make dramatic changes, and it's not easy to know how to evaluate/define what makes an effective and excellent teacher. I've team-taught a class with someone who spent the semester providing erroneous and out-of-date information to students but who got high teaching evaluations. Is he a good teacher because he presents information clearly, or he is a bad teacher because of the problems with his course content? I've also team-taught the same class with someone who did an outstanding job presenting interesting and innovative course content, but the students found him intense and unapproachable; his evaluations were lousy. Is he a bad teacher?
I don't know -- I am good at providing ideas for teaching materials and some aspects of the logistics of teaching, but not good at giving useful advice to people about how to be better teachers. That's a job for the education experts, as long as they don't spend too much time trying to convince us to exchange course content for pedagogical games with cute nicknames.
9 years ago