Line Graphs — Definition

Definition

A line graph plots values against an ordered variable, commonly time, and joins successive plotted points to show a pattern of change. It can display one series or several comparable series. The position of a point gives a level, while the change between points describes an increase, decrease or rate over an interval.

A high point is not necessarily the point with the fastest increase. Nor does joining observations prove exactly what happened between measurements. Reading a line graph requires attention to both axes, their scales and the meaning of each series before drawing conclusions about trends.