Fall 2009 Colloquia

Abstract
     This talk will summarize a series of studies examining student learning following learning activities in an online learning environment featuring an interactive visualization of the greenhouse effect. In the main study, 195 middle school students use an interactive visualization to learn about the greenhouse effect and global warming.  I measure changes in students´ conceptual knowledge and scientific reasoning skills following the model based instruction experience. A longstanding issue in science education research is the tension between teaching scientific content vs. scientific process or reasoning.  Following instruction and experience, students are able to engage in valid scientific reasoning in familiar or simple contexts (Chen & Klahr, 1999, Kuhn & Angelev, 1976).  However, there is still concern about overtaxing students´ cognitive resources when they are required to engage in activities that involve using scientific reasoning strategies to learn new scientific content. Using interactive models to teach science can help address the content versus process issue by allowing students to practice reasoning about scientific phenomena in rich contexts.  In this study, students use an interactive model to learn about the greenhouse effect.  Instruction prompts them to use a control variables strategy as they conduct multiple experiments with the model.  The main goal of this work is to measure changes in students´ content knowledge and scientific reasoning skills following a model based instruction experience.

     A major part of the data analysis focuses on students´ drawings of how the greenhouse effect happens.   They are viewed as an externalization of students´ representations of the relationship between key components and mechanisms involved in the greenhouse effect. Drawings from a subset of student data from one randomly selected teacher (N=50) were coded and analyzed. Out of the 50 participants, only 13% of the students generated drawings showing complete representations of the CO2/infrared energy interaction.   On the post-test 33% of them were complete representations that included the two necessary components (infrared energy and CO2) and the necessary mechanism (infrared energy reflection)

     Additional analyses presented will illustrate the connection between students´ scientific reasoning strategies and their conceptual understanding.  Findings show that students who use more effective strategies (like controlling variables) as they conduct experiments with the visualization have increased understanding of the target concepts.

References:

• Varma, K. & Linn, M.C. (under review).  Investigating the Impact of Technology-Enhanced Curricula, and Supporting Students´ Understanding of Complex Scientific Phenomena
  
  
• Clark, D. B., Varma, K., McElhaney, K., & Chiu, J. (2008). Structure and design rationale within TELS projects to support knowledge integration. In D. Robinson  and G. Schraw (Eds.), Recent Innovations in Educational Technology that Facilitate Student Learning: Perspectives on Cognition, Learning, and Instruction.  Information Age Publishing; Charlotte, NC.

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