A line graph is a type of graph drawn by using line segments to connect data points. Line graphs are one of the most commonly used types of charts. They are particularly useful for situations like illustrating changes that happen over a period of time or other variables. Below is an example of a line graph that shows the change of the weight of a hamster over a period of four weeks.
The example above depicts one of the simplest uses of a line graph. Line graphs can also be used to compare multiple sets of data over time. The line graph below compares the average temperature over the period of a year in Boston and Houston.
From the line graph above, we can see that the average temperature in Boston remains significantly below that of Boston.
Advantages and disadvantages of line graphs
There are many ways to use a line graph, but like any other type of graph, it is important to know when to use a line graph as opposed to some other type of graph or data presentation method.
- Useful for representing continuous data, such as change over time
- Allows possible extrapolation of data
- Having a line constructed from multiple data points can allow you to make estimates of missing data
- Allows comparison of two or more items to see if there is any kind of connection or relationship
- Can be difficult to determine exact values at a given point of the graph
- Too many lines, or even two lines that have values that are too similar, can make comparing data difficult