Two approaches to introductory courses in complex systems

Louisa Bradtmiller, Macalester College

I teach two introductory-level courses about complex systems: Introduction to Environmental Science, and The Earth's Climate System. As their titles suggest, one is quite broad and covers a range of topics in the natural and human world, while the other is more narrowly focused on a specific topic in Earth science, albeit one with significant links to human behavior. The courses have many similarities- they are both lecture-based, and both have required labs sections. The lab sections are used for inquiry-based activities, while lectures are a combination of lecture, discussion and occasional group activities. Aside from the content, the primary difference between the two courses is the way topics are organized (or not) and presented to students. I will use the rest of this essay to outline the two different approaches, and share some thoughts on what I see as the pros and cons of each as a strategy for teaching complex systems.

Introduction to Environmental Science is a course I 'inherited' -- it fulfills a major requirement (also a college-wide science requirement), and is taught every semester. As a first-year faculty member I wasn't looking for extra work, and so left the overall structure of the course intact. The course is explicitly divided into five topics: Biodiversity, Human Population Growth, Energy, Water Availability and Pollution, and Climate Change. We spent several weeks on each topic, including related lab activities, and then switched to the next topic. The Earth's Climate System is a course I developed with colleagues before starting this job, and it follows a more organic approach. We certainly cover different topics, but they are presented to students as a continuum of ideas and concepts that build on one another. In other words, we start with what was identified as the (or at least one) basic building block of climate science - the Earth's radiation budget - and build upon that to explore other things.

These two approaches seem to have affected students' understanding of complex systems in different but not unpredictable ways. The students in Intro. to E.S. demonstrated somewhat better mastery of each individual topic -- they were better prepared to answer exam questions about individual processes and specific information than their Climate peers. However, the students in the Climate course have (so far) excelled in answering questions that connect larger-scale processes and concepts together, while perhaps not doing quite as well with detailed questions about, say, Earth's radiation budget. As I stated, this is not unpredictable, but of course, student learning in the ideal course on complex systems would fall somewhere in the middle. So far, I have tried to split the difference by working with the Intro. to E.S. class to make explicit connections between topics, and by re-emphasizing specific facts and ideas several times throughout the Climate course.

This problem is familiar to anyone who has designed a course, a major, or a curriculum. How do we balance breadth and depth? In this case, breadth refers not so much to the range of knowledge covered (although this might also be applicable), but to the understanding of a complex system, and perhaps also to the breadth of ways students might be able to apply that understanding. As I continue to teach these and other courses on complex systems, I hope to find an organizational style that encourages both a complete grasp of the necessary factual information and the ability to connect ideas from different topics together in a deep understanding of the system as a whole.