An investigation of the relationship between scientific reasoning, conceptual knowledge and model formulation in a naturalistic setting

This study examined the reasoning discourse of two pairs of ninth grade students in the Midwestern region of the United States, The purposes of the study were to elucidate specific types of reasoning strategies that students use in ordinary classroom activities and compare the reasoning strategies used in an activity that required little domain-specific knowledge to one that required extensive domain-specific knowledge. Interpretive techniques were used to explore the students' thinking represented in discourse, writing and interviews. Results indicated that successful model formulation for both activities involved: recognizing the tenative nature of existing models; identifying laboratory observations as evidence and using evidence to modify existing models; and coordinating all mutually consistent knowledge propositions into a coherent new model. For the activity requiring substantial conceptual knowledge, both the generation of relevant knowledge propositions and their coordination with laboratory evidence were important in constructing an accurate scientific model.