What's in a word? Student beliefs and understanding about green chemistry

For the past decade, the College of Chemistry at UC Berkeley has iteratively redesigned general chemistry laboratory courses to introduce students to green chemistry concepts, while simultaneously using green chemistry as a relevant context to learn chemistry. To investigate the effectiveness of this curriculum we developed approaches to investigate student understanding of green chemistry. We adapted a constructivist educational framework to iteratively design fixed and free response items appropriate for large enrollment courses that probe student knowledge of green chemistry concepts and practices. Two free response items were designed to probe students' ability to define green chemistry and make green chemistry decisions in the context of a case study. A set of fixed response items were designed to probe particular aspects of green chemistry knowledge that were included in the course. Together, we used these items to characterize (1) changes in student understanding of green chemistry and (2) how prior "green" knowledge impacts student learning of new green chemistry principles in the general chemistry laboratory course. Analysis of student responses indicated that, on average, students demonstrated increased green chemistry understanding after completing this green chemistry aligned laboratory course. Students were able to integrate more normative green chemistry principles in their answers and began to indicate awareness of complex interconnected systems. Because the items focused on assessing student knowledge of green chemistry, rather than their self-assessment of knowledge, they provided valuable insight regarding students' prior green chemistry knowledge that will be used to develop future versions of the curriculum.