How people represent and reason from graphs

In this paper we examine how people represent graphical information. We present a constrained graphical reasoning task isomorphic in logical structure to a three-term series reasoning problem. Participants were shown pairs of simple line graphs (premise graphs) and were then required to verify a third line graph (conclusion graph). We found that participants reordered the premise graphs in order to construct integrated representations. The order of the terms in the premises (their figure) modulated the accuracy and speed with which participants subsequently verified conclusions against these representations. These findings suggest a role for analogical representation in graph comprehension and call into question the common assumption that graph comprehension processes may accurately be modelled using propositional representations only