Data visualisation

What is data visualisation and why would you want to use it?

Data visualisation can be an effective method of conveying information in a quick and engaging way. It can be useful when analysing and interpreting data to help identify patterns and trends which may not be visible in the raw numerical data. Illustrations like charts, graphs, infographics, and maps can visually transform large amounts of data into comprehensible information.

How do we use different kinds of visuals?

Visualisations often used to report school data are bar graphs, line graphs and pie charts. Each of these communicates data in different ways.

Bar and column graphs

Bar and column graphs are comprised of rectangular bars of lengths proportionate to the values they represent, and can be plotted vertically (column) or horizontally (bar). They are most useful when:

  • comparing different categories of the same type of data – for example, gender or performance

  • visualising large amounts of data about a particular category – for example, survey question data.

Line graphs

Line graphs are comprised of lines connecting different data points. They are most useful when showing trends over equal intervals of time such as weeks, terms or school years. These can also be used to compare changes of more than group over the same period of time.

For example, the line graph below shows changes in the averaged reading scores of Year 5 boys and girls across a school year.

Pie charts

Pie charts are circular charts which are divided into slices to visualise numerical proportions. They are most useful when comparing parts of the whole – for example, years of teaching experience of educators at a school.

You do not need expensive tools or software to create effective data visuals. Excel, free or paid online visualisation tools can enable you to quickly and easily create effective and appealing graphics.

To learn more about how to use, interpret and create data visuals well, access the following AISNSW professional learning courses:

What is educational data?
Making your numerical data work
Face to face Excel courses (please email for dates)

More complex graphs include box and whisker plots.  

Box and whisker plots

These are also called box plots. They are comprised of rectangular boxes and lines extending from each box. They are most useful when wanting to show both the central values and variability of a dataset.

For example, the box plot above visualises NAPLAN results for Year 3, 5, 7 and 9 students at a school. It shows the median score (green line), mean scores (black line), and the range of scores – the blue box being the distribution of the middle 50% of student scores; the whiskers, the top and bottom 25% of scores.