In summary, at the beginning of this episode the students interpreted the effect
of changing scales as a movement of the graph downward rather than as an effect on
its shape. Following the teacher’s intervention, they started to consider how scaling
of both axes affects the shape of the graph. Moreover, they were able to develop
manipulations for these changes to occur in order to achieve the desired shape. In
the process, they began to move between local and global views of the data in two
representations.