A line graph is used to represent information which changes over time. A line graph is plotted with points that are joined to create a straight line. Graphs are ideal for adding a visual representation to statistical data. They are brilliant for plotting data that couldn't be shown in any other chart; for example, 'How hot does it get each day of the month in August?' This question couldn't be well represented in a pie or bar chart as the scale is overtime.
What are the five parts of a line graph?
The X-Axis – The X-axis is the horizontal (across/flat) line that often represents the names, dates or times being measured in the line graph. For example, the day of the month would be measured here.
The Y-Axis –The Y-axis is vertical (upwards). This is typically the axis that shows a measurement, it always starts at 0. It's important that all measurements are split equally down the axis, just like the y-axis on all the other graphs the child can decide what is an appropriate scale to use. For example, the heat temperature would be shown here.
The Title – This is the first thing a reader will see when they look at your graph. It needs to be short, to the point our temperature graph could be ‘Daily temperature for the month of August 2023’.
The Source and Data –What data have you collected to plot in your graph? Is there more than one set of data to represent? Where did the information come from, is it data you collected or someone else? These questions are important to show in your line graph. Make sure to credit whoever owns the information you are using. If you need to show more than one type of data, for example, you want to show how the temperatures have changed in August over the years, then you could plot multiple lines on your graph and use different colours. If this happens it is important to write a key on the side of your graph to show what colour represents what year.
The Legend – This is vital for showing the reader what each line means. Write a short sentence explaining each axis, e.g. ‘temperature per day (in celsis)' for the Y-axis and 'Date' for the X-Axis.
Interpreting a line graph?
When we look at the line graph below, we can clearly see the pattern in daily temperatures. However, if we wanted to actually read from the graph, we would need find the first identifying factor, either the temperature or the day of the month, then draw a line from there to the plotted data point and then follow this up with another line to its corresponding fact.
For example, here we have identified that on the 14th it was 21 degrees and on the 25th it was 20degrees.
