Data Visualisation and Accessibility

Visualising data with charts, diagrams and infographics allows for complex data to be presented in a concise, digestible way. We use charting libraries as part of our web services and you will see them in use on this website.

But these graphical representations, while effective and visually interesting aren’t the most inclusive or accessible way to convey the data within them.

Poor use of colour, insufficient labels or alternative text when images are being used can mean that the information isn’t accessible, especially when used as the only means of communicating the information.

(Hyper)Text is the native format of the Web

When data is being represented as a chart, diagram or infographic, a clear and concise written text interpretation of what the graphics shows should be included in the body of the article. This allows the information to be delivered to the user regardless of the technology they use to experience it.

For example, the figure on this page is a sunburst chart showing my fictional family tree. I have one brother called Peter and my Father has two brothers called Mike and Leo whose parents Nancy and Fred. I have five cousins: Betty and Jenny are the children of Uncle Mike, and Mary, Ben and Jack are the children of Uncle Leo.

It is important that the text description is just as informative as the graphic. This is so that it provides an equivalent experience for people using screen reading software, or for those who may have difficulty in understanding the chart.

Alternative Graphics

Perhaps it’s best to think of charts, diagrams and infographics as ‘alternative graphics’ analogous to ‘alternative text’ used to provide alternatives to images via HTML’s ‘alt’ attribute. That way, we enforce good practice, and ensure that the information we’re publishing is accessible to all.