Accessible Graphs for Visually Impaired and Blind Users


We live in a visual world where data and content are presented using graphical interfaces. The data and content are presented in a variety of ways and in many cases visual content can be made accessible so that blind people can access the content using screen reader software and Braille displays. And despite the tremendous advances in the accessibility of websites, mobile apps, computer software and digital documents, still one area remains unanswered. Access to quantitative data shown in graphs and charts is not accessible to many people with visual impairment and blindness. Most graphs are presented as images that include the data in the graph. Although alternate text can be added to graph images - in most cases, the details provided in the alternate text do not provide full detail of the graph. It is also not easy to understand the various trends reflected in the graph such as average, minimum value, maximum and other details that can be felt through vision.

The Accessible Graphs Project aims to remove this barrier by developing a dedicated system designed for people with visual impairment and blindness, that will also help people who have difficulties perceiving or understanding visual data such as graphs and charts. The system can help the user by providing a simpler way to view graphs, and at the same time, to provide accessibility for screen reader users.

Experiencing the accessible graph

The graph is made accessible by a simple user interface that uses speech, tones and touch:

Also, the user can choose to hear the entire graph by pressing the read entire graph button.

Browser and screen reader support

Currently the system works best on Windows with the following screen reader and browser combinations:

How the system works

An end user with a visual impairment or blindness can access a given accessible graphs and navigate it using screen reader software and / or a Braille display. At any given moment, a user can get more information about the graph such as minimum, maximum, average values and more. In addition, while navigating the graph, the system produces a spatial sound that helps the user understand the trends of change in the graph – that is, an increase or decrease in the numerical value.

For example, a blind user can access a collection of 14,000 different stocks from all over the world, as well as currency exchanges, indexes and bitcoin prices, and review the trends of change and fluctuations in a graph. Anyone can experience the accessible stock graphs in the accessible stock web page. Just choose one of the technology companies and browse the accessible stock graph page.

Navigating the graph with a keyboard

Navigating the graph with a braille display

When using a Braille display, the user can navigate the graph using the navigation keys on the Braille display or keyboard shortcuts used by screen reader users. Each time the numeric value under the cursor changes, depending on the numeric value, the tactile output will lengthen or shorten in a way that illustrates to the user the relative height of the number relative to the other numbers in the value range of the graph. More detailed explanation can be found on the Accessible Graphs website on the Braille tutorial page. Here we’ll just leave you with a little taste of the interesting things a Braille display can draw:

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Our Vision

A system for making graph accessible can provide a solution to many accessibility barriers faced by people with visual impairments and blindness as students, as employees and as people seeking to be exposed to information displayed in graphs across the internet. One of the important benefits of a system for making graphs accessible, is the ability to help a more successful integration of people with blindness in workplaces where there is a need to collect and analyze graph information, such as financial, business, analysis, science and computer algorithms related jobs.

This project is funded by the Israel Innovation Authority, and is run by The Public Knowledge Workshop (a nonprofit organization). The funding for the project will end at the end of September 2020 and from there we hope that everyone who wishes to continue using the system can do so on our website, or by using the open source code.

Integrating accessible graphs on a website

Integration with Accessible Graphs is super easy.

All you need to do, is create a url with the data as part of the url.

See also