Connections Between Student Explanations and Arguments From Evidence About Plant Growth
Abstract
"In this paper we focus on how students connect explanations and arguments from evidence about plant growth and metabolism—two key practices described by the
Next Generation Science Standards. This study reports analyses of interviews with 22 middle and high school students post-instruction, focusing on how their sense-making strategies lead them to interpret—or misinterpret—scientific explanations and arguments from evidence. The principles of conservation of matter and energy provide a framework for making sense of phenomena, but our results show that students often reason about plant growth as an action enabled by water, air, sunlight, and soil rather than a process of matter and energy transformation. Many of these students re-interpret the hypotheses and results of standard investigations of plant growth such as von Helmont's experiment to match their own understanding of how plants grow. We also observed that students often improved their explanations and arguments when provided with scaffolds during the interview. We use these analyses to show how student beliefs and habits of mind can lead to alternate interpretations of both arguments from evidence and instructional explanations. We describe our progress and challenges developing teaching materials with scaffolding to improve students' understanding of plant growth and metabolism."