Middle school students often struggle to overcome misconceptions regarding climate change concepts. The Next Generation Science Standards may help students build understanding of global climate through engaging in science practices. However not all teachers prefer to teach science content primarily through practices. We studied how 143 students of two 8th grade teachers performed in pre- and post- tests. One teacher preferred teaching through science practices (Nadya), and the other preferred direct instruction (Ruth). We analyzed student responses to three sets of paired items that addressed the relationship between atmospheric CO2 concentration and temperature, human activities that increase atmospheric CO2, and evidence of modern climate change. For each pair, one item required content knowledge only, and a second item involved graph interpretation or reasoning. We investigated the following questions:
- Do differences in student outcomes exist between teachers who are more vs. less oriented toward teaching science through practices?
- How do students perform on climate-related items that fuse content knowledge with graph interpretation vs. items that only require content knowledge,
- How do students perform in providing evidence vs. reasoning?
- What are students’ climate conceptions and approaches to graph interpretation and reasoning before and after the unit?
Results/Conclusions
Student improvements varied by teacher. Nadya’s students began with lower pre scores and improved on five of six items. Ruth’s students began with higher pre scores and improved on only one item, which addressed content only. Ruth’s students performed better on this item than a paired item that fused content and graph interpretation. Nadya’s students performed equally well on content-only vs. fused items at both times. Student approaches to graph interpretation varied by teacher. Nadya’s students generally addressed points on the x-axis in post-test responses, whereas Ruth’s students generally described trends in the graph. For both teachers, students most commonly cited fossil fuels, cars, and deforestation as human activities that cause CO2 to increase. Industrialization was mentioned as a cause of CO2 increases by 25% of Nadya’s students, but only 10% of Ruth’s students. At both points in time, students of both teachers were better able to provide evidence of climate change than to support evidence with reasoning. Themes mentioned as evidence for climate change predominately included melting of ice or glaciers. Over 20% of Nadya’s students also mentioned animal migration. Teacher interpretation and pedagogical orientation are likely to affect student learning outcomes associated with climate change and science practices.