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Research on alternative conceptions in student understanding of a complex ecological problem: The carbon cycle.
Ebert-May, Diane*,1, Batzli, Janet1, Lim, Heejun1, 1 Michigan State University, East Lansing, MI
ABSTRACT- Learning theory indicates that students are continuously constructing meaning of information and experiences. During this process they often generate new or build upon existing alternative conceptions. We present research on student understanding of the carbon cycle which often elicits major misconceptions concerning cellular respiration, photosynthesis, decomposition, states of matter (i.e., gases have no mass) and conservation of matter. All of these concepts can be understood at a variety of scales, cells to ecosystems, where students seldom have the opportunity to make important connections. Therefore, we developed a relevant problem about the carbon cycle to enable students to reflect on, reveal, and revise their understanding in a meaningful way during a two-semester introductory biology course. We designed diagnostic questions and other assessments to gather data that track the development in students understanding over time. Assessment techniques include interviews, concept-mapping, objective questions, open-ended questions, and on-line instructional resources designed for students to dissect concepts and put them back together in meaningful ways. We used multiple representations of a carbon cycle problem to determine if students explanations were consistent and transferable. These data provide additional insight into students thinking about biosynthesis, source/sink, conservation of energy, and primary productivity. At the end of the second semester (cellular and molecular biology) students were asked a synthesis question about the carbon cycle designed for them to explain multiple concepts at multiple scales. This type of longitudinal study on alternative conceptions arising within existing course structures could provide opportunities for instructors to reflect on and revise teaching approaches or course scope and sequence. The carbon cycle, often skimmed over as a confusing image with arrows in introductory textbooks, represents a rich problem that involves many biological processes and concepts that can be returned to again and again throughout an undergraduates introductory biology curriculum.
KEY WORDS: education, research, alternative, conceptions