Corda Accessibility: Chart Compliance

SECTION 508 / CHARTS AND GRAPHS The intent of Section 508 is to provide equal access to all federal government Electronic Information Technology resources. This includes all federal employees and the interested public, including those with disabilities of any kind. One specific area of concern is presenting information in charts and graphs in a manner that makes it accessible to the visually impaired. Charts and graphs are used to portray data because they do so in an efficient and concise manner for sighted individuals. Charts and graphs are so popular because they convey a large amount of information very efficiently. They allow users to see trends and understand relationships that are otherwise not evident when looking at tabular data. This advantage is lost to those with impaired vision if they have no access to the information contained in the chart. The challenge is to make the data contained in charts and graphs accessible to the visually impaired in a usable and informative manner.

Screen readers have given the visually impaired a great deal of help in providing access to the information contained on the Internet. Screen readers do a good job of reading text, but have trouble with graphics. Prior to the advent of 508 legislation, charts and graphs were inaccessible to a screen reader. When a screen reader encountered a chart on a web page, it would announce “image” then continue on with the remaining text found on the page. The screen reader user was left completely uninformed as to the content of the “image”.

Web developers found that by putting data in data tables, they could increase the amount of information available to screen reader users. When reading a table, the screen reader reads all of the numbers contained within the cells of the table, giving the visually impaired additional information. The drawback to this approach is that the screen reader reads all of the cells horizontally across the page similar to the method of reading text. Thus if the top row of cells in the data table contains column labels, they would be read first. The succeeding rows are then read horizontally until all of the numbers in the table are read. This method can be confusing to understand because all of the data is presented without providing relationships between the data and the labels. Lengthy tables present even bigger problem since the data becomes even more remote from the row and column headings. When tables are used, sighted users don’t have the advantage of seeing trends and relationships that charts and graphs provide. It requires much more time to analyze data in tables, when compared to data presented in a chart or graph.

Another approach web developers have used is to insert “alt tags” with each image. When a screen reader comes across an image, it reads the alt tag, which contains a brief description, such as, “Pie Chart Titled Budget Statistics.” A typical alt tag provides no information to a visually impaired person except the type of image and the title of the chart. The information displayed in the chart or graph is accessible only to a sighted person.

Another method of providing charts and graphs that meet the intent of Section 508 is to provide a long description of each chart and graph. This description is accessible to the visually impaired through a [D] link (descriptive link) which the screen reader recognizes and announces the link to the user. The link can then be accessed and the full descriptive text read by the screen reader. This method provides the visually impaired the greatest access to information in a chart/graph. This method is also the best for sighted users, as they are able to enjoy the benefits of seeing data in a graphical format rather than just rows and columns of data. This method also provides a single path for both sighted and non-sighted users, instead of presenting data in two different formats.

Properly creating effective descriptive text has been a labor-intensive process requiring a person to view and understand the chart, then write a meaningful description that is accurate and has a consistent format. Because of this, many federal web sites have struggled to provide data in a meaningful format for both sighted and non-sighted users. For installations with a few charts and graphs the descriptions could be created manually. However, sites with a large number of charts or charts with changing data have an almost impossible task of providing descriptive text to make these charts accessible.

There is now technology available that will automatically generate descriptive text at the time the chart or graph is created. This eliminates the costly and time consuming manual creation of descriptive text. Agencies can now present data in the most effect format while also providing accessibility to all users. There is not a separate pathway for obtaining information for the sighted and the non-sighted. By automating the creation of the descriptive text, federal agencies can provide their data in a meaningful, accessible, graphical format without the expense of manually generating descriptive text for each chart and graph.

The intent of Section 508 is to provide all users of electronic information comparable access. The federal government generates a large amount of data that is useful to all citizens. As the government increases the utilization of the Web as a communication tool, the needs of all users of that information must be considered. Data is presented more effectively in charts and graphs because of the efficiency of that form of representation. For the visually impaired, this data can now be accessed through the use of screen readers and [D] link descriptive text. This technology provides access to data that was once unavailable. Technology should continue to expand access to all citizens so that they can be fully informed of the world around them.