Accessibility - Refactoring HTML: Improving the Design of Existing Web Applications - page 231

Pied-billed Grebe
</th>
<td>Uncommon</td>
<td>Very rare</td>
<td>Uncommon</td>
<td>Fairly Common</td>
</tr>
<tr>
<th abbr="mourning" scope="row">Mourning Dove</th>
<td>Common</td>
<td>Common</td>
<td>Common</td>
<td>Common</td>
</tr>
<tr>
<th abbr="worm eating" scope="row">
Worm-eating Warbler
</th>
<td>Uncommon</td>
<td>Rare</td>
<td>Very rare</td>
<td>Not Present</td>
</tr>
</table>

Motivation

Although tables are an excellent means of presenting certain kinds of data to sighted readers, they challenge
blind readers who must access a page linearly. Consider the code immediately preceding this paragraph.
Presented linearly in HTML, does it really make a lot of sense? This is how a blind user is likely to see it.
Presented two-dimensionally as in Table 6.2 , it's a lot easier to read.

Table 6.2. Species Occurrence

Species Spring Summer Fall Winter

Pied-billed Grebe Uncommon Very rare Uncommon Fairly common

Mourning Dove Common Common Common Common

Worm-eating Warbler Uncommon Rare Very rare Not present

Many sight-impaired users prefer to just get a quick summary of a table rather than trying to read the entire
thing. When they do need to drill down into a table, it's very helpful to have marked-up headers for rows and
columns that help them determine where they are.

Potential Trade-offs

Captions are shown to sighted users as well as users with screen readers. If you really don't want a caption, this
can be a problem. In this case, you might choose to provide a title attribute instead.

However, even fully sighted users often prefer to be told what a table means rather than carefully inspecting the