What can we learn by comparing students' diagram-construction processes with the mathematical conceptions inferred from their explanations with completed diagrams?

Despite recent research interest in student-created diagrams, little research has systematically investigated students' diagram-construction processes, meaning the order and manner in which students create markings as they physically generate diagrams. In this study, the authors characterise the various processes students use to create diagrams that represent a quadratic motion situation involving increasing speed, and explore how these diagram-construction processes are related to students' conceptions of speed as inferred from their explanations with their completed diagrams. Previous literature suggests contrasting predictions regarding whether or not students' diagram-construction processes are closely related to students' inferred conceptions. The authors see the study as having value for research and practice by raising new questions related to diagram- construction processes, pointing to the potential formative assessment value of attending to diagram-construction processes, and demonstrating the need for the development of theory to explain the relationships identified by this study. [Author abstract, ed]