  In this paper, we reflect on the educational challenges and research
opportunities in running data visualization design activities in the context of
large courses. With the increasing number and sizes of data visualization
course, we need to better understand approaches to scaling our teaching
efforts. We draw on experiences organizing and facilitating activities
primarily based on one instance of a master's course given to about 130
students. We provide a detailed account of the course with particular focus on
the purpose, structure, and outcome of six two-hour design activities. Based on
this, we reflect on three aspects of the course: First, how the course scale
led us to thoroughly plan, evaluate, and revise communication between students,
teaching assistants, and lecturers. Second, how we designed learning scaffolds
through the design activities, and the reflections we received from students on
this matter. Finally, we reflect on the diversity of the students that followed
the course, the visualization exercises we used, the projects they worked on,
and when to key in on simple boring problems and data sets. Thus, our paper
contributes with discussions about balancing topical diversity, scaling courses
to many students, and problem-based learning.
