In compiling the questions to target the gravity concepts presented above, we were careful to separate as much as
possible general aspects of “force” from the specific “gravitational force.” Therefore, there is little to no
emphasis on Newton’s laws, as the Force Concept Inventory (FCI) is a more appropriate test of Newton’s laws
and, more importantly, it repeatedly shows that students have a poor understanding of forces (Hestenes, Wells,
and Swackhamer 1992). It is for this reason that in formulating the gravity conceptual questions we were careful
to emphasize aspects of the causes, effects, and extent of gravity, rather than general force concepts.