Code. The criteria used to classify the responses
R1 No response or no explanation
R2 No understanding: irrelevant explanations or answers such as “I do not know”, ”I have no idea”
or ” I do not understand”
R3 Misunderstanding: explanations that attempt to describe the target concept but do not match the
scientific conception
R4 Partial understanding: incomplete but correct explanation
R5 Sounds understanding: explanation that includes all components of the science concept