Types of diagram

Statistical information is often shown using graphs and other diagrams. These can be easier to read than lists of numbers.

You should be able to read and draw the following:

Example of 4 types of graph - barchart, histogram, line graph, pie chart

The type of graph you use depends on the type of data you want to represent.


  • Discrete data is best represented using bar charts.
  • Continuous data, for example temperature graphs, would usually be line graphs because the data is .
  • When you are showing percentages or dividing up a total amount a pie chart would be suitable.
  • When you have two variables, such as marks in a Maths test and marks in a Science test, then a scatter diagram would be the one to use.

The other thing you need to remember is that all graphs need ‘SALT’. Make sure you remember the following information:

S = Scale

A = Axes

L = Labels

T = Title