Teaching Students to Work Within the Environmental Analysis Literature

Deborah S. Gross, Department of Chemistry, Carleton College
March 2, 2010

I teach a course entitled "Environmental Analysis" (CHEM/ENVS 328) which requires any 200-level chemistry course as a prerequisite. Beyond that, anything is possible. In the course, we use the primary literature as our textbook in an exploration of the types of quantitative analyses that researchers are carrying out in the real environment. In the course, we hope to directly address many aspects of each paper including the environmental context, the measurement principles used, relevant regulations with particular emphasis on any regulated measurement methods, and the basic scientific background. This not only requires students to learn a variety of complex material about complex environmental and analytical systems, it requires them to assemble it into a coherent framework through which to assess the paper under discussion. Because the environmental system is so broad, in that the papers we discuss could range from the analysis of mercury in tuna to an assessment of air toxics in Beijing to determination of anthropogenic CO2 in the ocean, there is no possibility that students will have enough specific knowledge to assist them in understanding all of the work we discuss. Additionally, the class as a whole is responsible for choosing the papers that will be addressed throughout the term, so there is no lead-time for me to prepare class discussions in detail. Thus, I find that my goal as the course instructor is more that of a facilitator, and I will describe here how I have been doing this in the various offerings of this course.

The most useful strategy that I have adopted for helping students decide what they need to learn to fully understand a paper about an environmental analysis topic is simply to break down the topics in a reproducible way. Because of the various goals of my course, we emphasize the following three areas:

1. the scientific context of the paper (e.g. toxic properties of mercury, where it comes from, and how it gets into the tuna);
2. the experimental techniques used and their benchmarks (e.g. how the mercury in the tuna is sampled and measured, the details of the measurement principle and limits of detection, as well as any standard methods used for analysis of mercury in tuna); and
3. how this compound/class of compounds is regulated, if it is, and what the motivations and issues are for these regulations (e.g. who cares and why).

Students sign up in pairs to lead discussions (to be the "local expert") on these three topics for the various papers, and I enforce that each student leads a discussion in each of the three topics for at least one paper during the course. The discussion of each topic for each paper tends to take approximately one class period. This strategy serves to create students who have specific and relevant knowledge about various aspects of the paper, to give them a venue to teach the rest of the class what they have learned, and then to participate in the group effort of putting it all together. The students who don't lead a discussion on a given paper have the assignment of bringing written questions to the discussions.

The strengths of this approach are that the students are given a narrow slice of a complex topic to tackle with a peer and then to share with their classmates. This is, presumably, more manageable for the students than asking them to tackle all of the parts of a given paper and to help their peers understand the complexities of it. I have found that the defined roles for each local expert, and the fact that they have to take on each role at least once, also allows them to generate good questions to ask each other in the various discussions that they don't lead, because they are aware of the types of questions that might be asked in that area from other examples. This approach also means that it is the class that does the overall evaluation of the paper and grapples with the whole package of information in all of its complexity, rather than the individuals, and I can assist in managing the discussion.

As alluded to above, one of the challenges of this approach is the role that the instructor takes in the discussions. I find that my role has settled into the following: I am prepared to facilitate the discussion on each topic on each day, but I hope not to do so. I typically don't know all of the specific details that the student experts bring to the discussion, but I make sure I am conversant in the big picture, and that I have a list of discussion-questions that I can pose to the students to get them thinking about aspects of the topic that the student experts may not think about. The students tend to find it challenging to sort out their jobs as local experts in both directions. They are wary of bringing too much detailed information about their sub-topic because they feel that too much information in any one area might skew the conversation about the paper as a whole. They are similarly wary of bringing too much of the context and big-picture evaluation of their topic because they fear they won't be detailed enough, and also because they haven't always developed the perspective to know what the context actually is. A transformation typically occurs during the course, with students getting better and better at navigating what seems initially like a conflict. My role as a faculty member in this process is to help them assess for themselves what the right balance is in any given situation.