I posted earlier about some reflections on fall 2014’s Astronomy 2022: The Origin of the Universe. In that post, I mentioned using Astronomy Labs: A Concept Oriented Approach by Emily Rice and Nate McCrady. Emily asked me for some more details about how I used the labs in a large class, so here they are.
My understanding is that the labs in the book are designed to be done in a two-or-three hour lab session. My classes were 50 minutes, so my approach was to split the labs up into smaller pieces. This wasn’t tricky since most of the labs were already divided into sections. In some cases I asked students to do a section as pre- or post-class homework. In other cases, I just left out sections entirely; there were a few that were not well-aligned with the rest of the course.
In class, I generally interspersed “lab” work (I called them exercises rather than labs as I thought that sounded less threatening for non-science students) with mini-lectures. The students worked on the exercises in groups of 3 to 5 for 10 to 20 minutes; I used a similar structure when doing problem-solving in large first-year physics classes. While the students were working, I and a teaching assistant walked around, helping if they were confused, or prodding them to work if they were off-task. In my experience, students’ biggest problem was just getting started: if it takes you 5 minutes to find your worksheet and a pencil and read the directions, you don’t have much time to finish the exercise. If I were doing this again, I’d instruct students to read over the exercise before class. Maintaining students’ focus on the work was sometimes difficult: ideally there would be more than 2 instructors for this class size, but my TAs’ other duties made that tough to arrange. After the 10-20 minutes were up, I filled out the exercise sheet with the class using the classroom document camera.
The exercises were marked for completion only: at the end of class each group handed in their completed worksheets for a participation mark. Marking for correctness could have been done, but of course that would have used a lot more TA hours. In any case, I didn’t want students to be worried about speed or correctness. I was more interested in having them make the effort to understand the reasoning involved, so I think marking for participation was OK. In noting down who had done the exercises (I did most of this myself, and could do a whole class worth in about an hour), it looked to me like most students had made an honest effort.
Overall, I think the exercises in “Astronomy Labs” were a useful pedagogical tool for helping the students think during class, as opposed to just listening to me talk. I’m not sure that I explained this rationale well enough to them — I felt like the resistance to active learning was high at times — and I would try to improve that in a future version of the course. I would also work on making sure the labs were tied directly to the learning obejctives and exams, either by adjusting the choice of labs, or adjusting the objectives/exams. I liked the fact that I could select just a handful of labs from the comprehensive set, and make up a workbook with a relatively low cost for the students. I would definitely urge other instructors of introductory astronomy courses to give these labs a try.