Data Viz Accessibility in 2021

In 2021, we in UW-IT Accessible Technology Services received a sizeable increase in requests for accessibility consultation related to data visualizations. On March 29, Hadi Rangin and I joined Kelly Gupton, Tableau’s Senior Director of Product Management, at the UW Tableau User Group (TUG) for a presentation and conversation on “data viz” accessibility. The recording of that session has been hosted in the TUG Canvas course, but was rotated out recently to make room for new content. Nine months after that meeting, we continue to receive requests for the recording, so we’re now hosting it in our own Accessible Technology Webinar archives. The archive page includes links to the PowerPoint slides (a general overview), and a web page of links to example sites and dashboards that were featured in the presentation.

To summarize, there are several best practices for creating Tableau dashboards to make them more inclusive. These are well-documented on the Tableau Accessibility FAQ, and anyone creating Tableau dashboards should devote some time to learning and applying these best practices. However, despite best efforts from dashboard creators, some users with disabilities, including screen reader users and sighted users who are physically unable to use a mouse, will find it very difficult, if not impossible, to access Tableau dashboards in any meaningful way.

There are similar best practices available from Microsoft regarding Accessibility in Power BI. but our tests with Power BI dashboards have yielded similar results to our tests with Tableau. A sighted user with a mouse can very easily explore data and trends within a visualization and quickly come away with a deeper understanding; whereas users who don’t have the ability¬†to use a mouse or view the visualization do not have a comparable experience, and often have no idea what information is being presented in a dashboard, or how to navigate it.

In order to make a Tableau or Power BI dashboard fully accessible given the current state of accessibility of these products, an alternative version of your dashboard will likely be required. There are two excellent examples of this at the UW:

  • UW COVID-19 Case and Vaccination Tracking Dashboard: This is a dynamic site, updated nightly. The data is presented in a Tableau version, with a link to view a text-only version of the dashboard. The “text-only” version provides access to the most critical data, using accessible HTML headings, tables, and summary text. Both versions draw from the same source data; they’re just presented in different ways for different users.
  • UW Fast Facts: This dashboard is provided in multiple formats to meet the needs of a variety of users. In addition to the Tableau version, there are links at the top of page to a text-only version (which, like the previous example , presents the same data using accessible HTML headings, tables, and summary text), as well as a PDF version (suitable for printing).

Our presentation at the TUG meeting included a quick look at Highcharts as a possible alternative.¬†Highcharts has put tremendous effort into making their dashboards accessible to a full spectrum of users. For example, keyboard users can navigate and interact with data points, menus, and other controls using the keyboard only (no mouse required); screen reader users can navigate, explore, and interact with dashboard content; users who can better “visualize” data trends using sound rather than sight can play charts using sonification; users of voice input software can interact with dashboards using voice commands; and much more. See more details about these and other features, including accompanying videos, on the Highcharts for Accessibility website.