Beyond Lists: drawing causal diagrams for experimental design in secondary science

The staple activity in experimental design is the production of a list of variables: what will be changed, measured, and kept the same. Yet, while the list proports to be specific, it actually conceals the causal relationships between the variables unless extended text is added. This hampers understanding and communication. Instead, students can create a causal diagram, which, in my experience, increases engagement and comprehension. In this article, I’ll demonstrate how to build and interpret these diagrams and how to implement them with students of any stage of secondary science education.