Secondary students’ evaluation of inappropriate strategies of reasoning about evidence under a scientific explanation

This study explored potential factors that could affect the development of students’ strategies for evaluating scientific evidence. Thirty-six students from Grade 7 were asked to evaluate the evidence from an investigation involving force and motion. They were shown three inappropriate responses to reasoning about that evidence. They were then asked to evaluate these responses against an informational text that conveyed the scientific explanation with Galileo’s thought experiment. Participants’ verbal responses to reasoning about the inappropriate responses to the informational text were transcribed and analysed qualitatively. We found three factors that influenced strategy development: the students 1) kept the conflict between the competing claims of the domain unresolved, 2) doubted the validity of the inference from the thought experiment and 3) mistakenly assessed the plausibility of the competing claims. Implications for explaining the development of reasoning about scientific evidence and for instruction are discussed.