Section 4.1: Defining Accessible Data Tables, Part 1
What are accessible data tables?
Accessible data tables are tables that are designed and marked (in the code) such that users of assistive technology can understand the purpose of the table and how specific data entries relate to the columns and rows of the table.
A data table "uses grids to organize information about relationships within the data set" [ 3, p.303 
]. Typically, the information in the table is interpreted by the visual relationship it has within a particular column or row.
Screen readers and data tables
In the table "Fall 2006 Exhibit Schedule" below, a table is used to associate dates and descriptions with specific art exhibits. The user is expected to understand that "September 9-30" is the "Date" for the "Faculty Salon Exhibition" based on the headers of the relevant column and row headers for the entry "September 9-30".
| Exhibit | Date | Opening Reception | Description |
|---|---|---|---|
| Faculty Salon Exhibition | September 9-30 | September 9, 6-9 p.m. | Recent work by faculty artists in the Department of Art and Art History |
| All Together Now | October 7-28 | October 7, 6-9 p.m. | Work by alumni of the Department of Art and Art History |
| Intersections | November 4 - December 2 | November 4, 6-9 p.m. | Work of two alumni from the Department of Art and Art History paired with their faculty mentors |
If a screen reader read straight through this table, in "say-all" mode, it would use a linear approach. It reads the table left to right, top to bottom, as it does with text content on a Web page. So this table would sound like this:
Table with 5 columns and 5 rows
Fall 2006 Exhibit Schedule Exhibit Date Opening Reception Description
Faculty Salon Exhibition September 9-30 September 9, 6-9 p.m. Recent work by faculty artists in the Department of Art and Art History
All Together Now October 7-28 October 7, 6-9 p.m. Work by alumni of the Department of Art and Art History
Intersections November 4 - December 2 November 4, 6-9 p.m. Work of two alumni from the Department of Art and Art History paired with their faculty mentors
Table end
In this example, the relationship of the data in any specific cell to a particular column is lost because the screen reader is in "say-all" mode. The relationship to a row header is also easy to lose in long rows in "say-all mode". But in "table-navigation" mode, those relationships are preserved. That is, tables have the correct structural markup in the code and are presented with any descriptive, orienting information that may be needed for more complicated tables, screen reader users can use table-navigation commands to check where a specific data entry is in relation to its column and row header.
For example, JAWS users have the following strategies available for navigating correctly coded tables:
- The whole table can be read line by line, either continuously or with sections selected manually.
- With the keyboard command Alt+Ctrl+Left (or right) Arrow the user can move along rows and JAWS reads out the heading of the actual column plus the content of the cell. Users can also read up and down columns in a similar way.
- With the focus in a particular cell, the keyboard command (Alt+Ctrl+Num Pad 5), will cause JAWS to present the information relating to the selected cell. That is, the cell content and, if the table has been coded correctly, the associated row and column headings. [ 2 ]
Activity 1: Example of JAWS reading a navigation table with key navigation
The table below presents class information for 4 class days. This recording of JAWS reading the table is how it would sound when a user is navigating with some of the keyboard commands.
Example of JAWS reading the Blindness and Visual Impairments table. | Date | Topic | Reading | What's due |
|---|---|---|---|
| September 10 | Blindness & personal narrative | Mehta, Sound Shadows, Chs. 1-7 | Post Reading Response and Journal of Mouseless Week to Forum |
| September 12 | Equivalent alternatives | MaxAccess, chs. 7&9; checkpoints and standards addressed in these chapters. | Place completed ALT text exercises in Teacher Folder |
| September 17 | Blindness: orientation & mobility | Mehta, Sound Shadows, Chs. 8-end; Slatin, Dillon Chronicles (online) | Sound Shadows 2 Reading Response to Forum |
| September 19 | Orientation & navigation on the Web | WCAG 1.0 Guideline 3 (all checkpoints); Guideline 12 , Guideline 13 , esp. Checkpoints 13.4 and13.6; Section 508 paragraphs (i) and (o) |
Skip navigation, orientation, markup exercises to Teacher Folder |
