Guideline 4
Provide access to data in tables for all users with disabilities.

Reading and manipulating tables is an important way of processing scientific information and is a particular problem for blind users. Using data in a table requires referring to the headings for the row and column in order to interpret the information in a single cell. When navigating tables in most current educational software blind users don't even know what cell they are in at any time, or the column and row headers. A standard method for providing programmatic information about cursor location and which headers apply to each cell will provide compatibility with assistive technologies that support the standard. One such standard is included as part of the HTML 4.0 specification from the World Wide Web Consortium (W3C). In addition, user agents (the browsers or other tools used to read the information) must include all the navigation commands users need to obtain the information in context.

Users with physical disabilities may be unable to manipulate tables in software when the user interface requires use of a mouse. Ensuring full keyboard control of tables should meet the needs of these users.

Checkpoint 4.1
Design all HTML-based tables in accordance with Web Content Accessibility Guidelines published by the Web Accessibility Initiative.
Priority 1
Producing data tables in conformance with the Web Content Accessibility Guidelines exposes crucial information about the structure of a table. See www.w3.org/TR/WAI-WEBCONTENT for more information.

Checkpoint 4.2
Ensure access to HTML-based tables in accordance with User Agent Accessibility Guidelines published by the Web Accessibility Initiative, or the interaction of a stand-alone user agent with tables.
Priority 1
The combination of accessibly written HTML tables and appropriately designed browsers or other user agents gives blind students access to tabular data. To make software compatible with assistive technologies, follow the WAI User Agent Guidelines in designing or choosing a tool for viewing tables. As an alternative, allow users to browse the product content using a more compatible browser instead of the browser provided within the program. A disadvantage of this alternative is the need for users to change context from the data table embedded in instructional materials to another piece of software, thus detracting from educational objectives. Examples of tools that include table navigation features for use with properly written HTML tables include:

Home Page Reader from IBM
www-3.ibm.com/able/hpr.htm

pwWebSpeak from isSound
www.issound.com/issound/catalog/catalog_pwwebspeak.html

Checkpoint 4.3
Provide equivalent access to data presented in tables not produced in HTML.
Priority 1
The User Agent Accessibility Guidelines for techniques creating an accessible interface are crucial to making tables accessible to blind users even when tables are not created in HTML. This is particularly true for dynamic tables which the user can edit. Another means to make tabular data available when it is part of static content is to provide pre-recorded audio or pre-produced braille text.

Technique 4.3.1
Create an accessible interface to non-standard tabular data
The best way to provide access is to use the checkpoints and techniques of the User Agent Accessibility Guidelines to create an accessible interface for tables. Include commands for navigating, identifying the current cell in context, and getting an overview of the structure and content of the table.

Technique 4.3.2
Allow users to open tables in another program that provides an accessible interface
Another approach to making data accessible is to provide the data in a format compatible with common spreadsheet applications. Users can then open the data in their standard spreadsheet and use the accessible interface of that program. Using comma-separated variables (.csv format) will also permit the file to be read sensibly by a user with a screen reader treating it as a text file. The disadvantage of this approach is that users must change context from the data table embedded in instructional materials to another piece of software, which may detract from the educational objectives of an interactive lesson.

Technique 4.3.3
Provide alternative access to static tables
For tabular data which the user cannot change, pre-produced audio can provide useful access. The entire data table can be read aloud, or the equivalent script can be provided in text. Techniques for how to best read tables of data are available from the National Braille Association Tape Recording Manual. (See Appendix 4, Guides to Spoken Mathematics.)

Tables can also be created in braille, though there are formatting challenges, especially for long lines of text. Professional brailling firms can advise the best way to braille tables. (See Appendix 2, Braille and Tactile Graphics Production Resources.) Once created, the set of brailled tables can be made available either through the publisher's distribution mechanism or through an arrangement made with the braille production facility. Availability of brailled tables should be clearly documented in product help and in any appropriate teacher support materials that may accompany the software. Availability of brailled tables should also be listed with the American Printing House for the Blind, a central source of information on how educators can locate accessible materials, listed in Appendix 2.