As an online Atlas, it is essential that the visualisations we choose communicate the key messages appropriately. We want our users to interpret what they see correctly.

Developing these visualisation strategies isn’t straightforward. We need to incorporate the uncertainty associated with the spatially smoothed estimates. For example, if people living in an area have a 20 per cent higher risk of being diagnosed with cancer than the national average, is that an important difference? Could it just be explained by random variation? We also need to consider how people understand visual images. For instance, do people prefer pie charts or bar graphs? Which type of graphs do people interpret more accurately? Does this depend on people’s backgrounds and experience? Does it vary according to the information they are seeking? These are only a few of the many questions we have been asking during the design process.