At Southwestern University, we offer a one-semester analytical chemistry course, Instrumentation in Environmental and Biological Analysis, that is required for chemistry majors and is an upper level elective for biochemistry and environmental studies students. As the only lecture course in our curriculum focusing solely on analytical chemistry, the class first provides an introduction to the discipline through such topics as calibration methods and analytical figures of merit. We then discuss chromatographic theory, separation methods (e.g., gas and high-performance liquid chromatography; capillary electrophoresis), mass spectrometry, and molecular spectroscopy—all with a particular focus on environmental and biologically relevant applications. Topics such as basic statistical analyses, extraction methods, and sample preparation are introduced in a separate project-based lab course, the Advanced Laboratory in Analytical Chemistry.
As part of a larger grant-funded pedagogical initiative, the Instrumentation course was completely re-designed in 2015 to incorporate student-centered active learning. Small groups (3 students each; 4 groups total) are assigned at the beginning of the semester and the groups collaborate on worksheets or other activities  during each class period. For some topics such as capillary electrophoresis and gas chromatography, students are assigned a short reading prior to class to provide them with foundational knowledge of the subject. In-class activities then expand upon the reading by encouraging students to use chemical principles to further understand and explain the topic or to apply their knowledge to new situations through problem solving. For other topics such as chromatographic theory and calibration methods, students come to class with little prior knowledge then work collaboratively on POGIL (process-oriented guided inquiry learning) style worksheets  that encourage them to construct their own understanding of a particular subject. Throughout the semester, working effectively with other students to cooperatively solve problems is emphasized as an important aspect of the course and is also articulated as an expected learning outcome on the course syllabus. In fact, the quality of each student’s participation in group work activities during the course is assessed at the end of the semester and contributes to a portion of their final grade. In addition to their class participation, students are also assessed through weekly homework assignments, primary literature article assignments, two in-class examinations, and a final exam.
Prior to 2018, the final exam for the course was structured similarly to the in-class exams but was longer. Over half of the final exam was based on new material (covered since the last in-class test) with an emphasis on application questions such as selecting the detector best suited for a particular chromatographic analysis or predicting the elution order of a group of analytes. The exam also included higher order questions requiring students to evaluate analytical data and reach conclusions along with some lower order questions (e.g., asking students to explain the operation of a particular instrument component). At Southwestern, final exams are scheduled for 3 h and the test was designed with a sufficient number of questions (usually around 20) that most students required the full time to complete the test.
Because of the emphasis on group work in my Instrumentation course, I was intrigued with the idea of adding a group component to the final exam for the class. I first suggested the idea to the students in my course in the middle of the Fall 2018 semester. At that point, they had been working with their group members for about 2 months and were comfortable expressing and debating their ideas within the classroom setting. However, the in-class exams for the course were all completed individually, so students were concerned about how the grading would work. I explained that they would complete an individual written exam during the first 2 h of the final and it would count toward 75% of their exam grade. Students would then spend the next hour working collaboratively in their regular groups to answer a subset of questions from the written exam, present their answers to the class, have the opportunity to discuss, and revise their answers; then, all receive the same group grade (counting 25% of their final exam score). I also provided my rationale for adding a group component to the final exam: my wish to make an important assessment both more collaborative in nature and better aligned with a central aspect of the course, the focus on small group work. We further discussed the option as a class and the students were interested to try it.
For my final exam with a group component, I reduced the overall number of questions to allow students to complete the written portion of the test within 2 h. Compared with my previous final, I maintained a similar mix of questions for the first part of the exam—primarily application questions but with a few lower order questions—and created a second section containing four multi-part higher order questions that focused on key topics we had discussed throughout the course (e.g., Beer’s Law, chromatographic theory, calibration, and a summative question that provided students with a set of chemical problems then asked them to select the most appropriate instrumental technique for an analysis and explain their rationale). After submission of the written portion of the exam, students convened within their regular groups and each group was assigned one of the four problems from the second section of the test. Students in the four groups were given 15 min to work collaboratively on the questions, and each group was provided with a poster-size self-stick easel pad and markers to record their answer. I circulated through the classroom while the groups were working and although I provided clarification when groups had questions, I did not facilitate their discussions. Each group then had ~ 10 min to present their answer to the class, discuss it with their peers, revise their response if necessary, and decide on a final answer. I then provided immediate feedback on their answer and assigned a point total for each question. I set a timer during this portion of the final to ensure that we stayed on task since lively discussion followed each of the group presentations and my assessment of their answers.
Because the groups had already been working together all semester, the students felt comfortable discussing their ideas and responding to feedback from their peers. As a result, even before the full-class discussion, the quality of answers was much better—with more nuanced analyses and greater attention to detail—than what I later found when grading the written individual exams. For each of the four questions, the groups modified and further improved their answers after feedback from their peers, debate, and discussion. Although the answer quality was better when compared with students’ individual exam responses, the class still did not earn a perfect score on the group component of the final. However, the average for the group component (91.5%) was substantially higher than the average grade for the same questions on student’s individual exams (69%). This difference in scores also highlights one of the most rewarding aspects of the group final: I heard so many “aha moments” as students came to a new or better understanding of a particular concept while talking in their groups, as a class, or responding to my feedback once their final answers had been submitted.
My students also reported a positive experience with having a group component added to their final exam. Some were initially apprehensive since the format was quite different than any they had experienced previously but they enjoyed the interactive nature of the final as well as the opportunity that they were given to correctly answer questions that they had missed on their individual exams (which also helped to improve their grades). Students noted that being able to think through the questions individually during the written portion of the test was particularly helpful for the group component. They also appreciated having the opportunity to learn from others in the classroom while working together to determine the best answer to a question. Reflecting on the experience, I felt it was important that the students had been working in groups consistently throughout the semester and had developed a supportive and close-knit community. Their strong camaraderie formed a foundation for their success working collaboratively on a high-stakes end of the semester assessment. The challenging nature of the questions was also a key aspect of the final since it spurred considerable discussion and debate among both the groups and the full class. Although the questions were difficult, scaffolding similar open-ended higher order questions throughout the semester through in-class activities, homework assignments, and in-class exams helped students rise to the challenge. One difficulty that I encountered was administering the group component of the final to a student in my course who had academic accommodations to receive extra time when taking exams. However, I was able to individually work with the student to take the written final during a longer testing slot earlier in the day which allowed the student to participate in the group portion of the exam with the rest of the class.