Maximum Accessibility: Making Your Web Site More Usable for Everyone By John M. Slatin,, Sharron Rush
Table of Contents
Chapter 5. User Experience: On the Bus
The trouble with tables is that they're meant for the eye, not the ear. They also make significant cognitive demands. To understand a table, you have to be able to read in two dimensions (horizontal and vertical, x and y) simultaneously, matching up the contents of individual data cells with row and column names that often provide only slender clues about the relationships the data embody.
Web designers aiming for maximum accessibility have to understand and address these challenges. People who rely on screen readers and talking browsers including both people who are blind or visually impaired and people with cognitive difficulties such as dyslexia have to hold row and column headers in their minds as the screen reader reads from cell to cell across each row. As the screen reader moves down from one row to the next, it becomes harder and harder to remember those row and column headers; the table sounds more and more like a list of meaningless numbers.
People with disabilities aren't the only ones who have trouble understanding tables. Design guru Edward Tufte has spent much of his career demonstrating how hard it is to understand the visual display of quantitative information and how devastating the consequences of poorly designed information displays can be. The explosion of the space shuttle Challenger in 1986 is his case in point. Tufte argues that poorly structured charts made it difficult for NASA decision makers to grasp the strong correlation between low temperature and O-ring failures like the one that caused the fatal fuel leak aboard the Challenger. The following examples aren't quite so dramatic, but it is worth keeping in mind that many people rely on the information presented in tables to make routine decisions that affect their day-to-day lives looking up bus schedules, for example.
