Practical accessibility testing for data visualisations

Since the pandemic we've seen an uptick of charts and data visualisation shared by news, government, and health organisations. Most COVID-19 data was presented as images on social media without alternative text-descriptions, or as interactive charts that were often too complicated to understand, or didn't work with increased font size, keyboards, screen readers, and other assistive devices and settings. Because of this, many people with disabilities or varying levels of education and data literacy were excluded from receiving important health information—discrimination with fatal consequences. When we think about data visualisation accessibility, we often think "colour blindness", but what about total blindness? What about using the chart without using a mouse? What about different zoom-levels, font-size and screen widths? In software, our applications are becoming increasingly data-driven, with lots of great JavaScript libraries that produce beautiful charts—currently (May 2023), however, almost all of them have critical accessibility issues. In this session we'll test some data visualisations with keyboard, screen reader and other accessibility testing tools. We'll also briefly cover alt-text for static images and data visualisations, JS chart library recommendations, and where to learn more.