Web Design in a Nutshell, 3rd Edition

Check for Linearization

When creating a layout table, it is important to be aware of how well your table will linearize when presented in a non-visual browser. Linearization refers to the order of the content when all the table formatting is removed. Screen readers read content in the order in which it appears in the source document, as though there were no markup there at all.

Tables are said to linearize well when their contents appear in a logical order in the source document. In general, it is preferable to get readers to the main content as quickly as possible. Unfortunately, the way many layout tables are constructed leads to the side column content (long lists of links and other sidebar-like information) appearing before the main content. The table in Figure 13-15 shows a typical (albeit simple) three-column layout table with a masthead.

Figure 13-15. A typical layout table

While it is perfectly clear what to read first when rendered visually, a look at the source reveals that users with screen readers will need to listen to the big long navigation list in “Sidebar 1” before they hear the main feature. This is a simplified example of a table that does not linearize well. Complex layout tables that are typical in everyday practice have far more egregious linearization problems.

 <table width="700" border="0" cellpadding="4"> <tr> <td colspan="3"> <h2>Exciting Page Masthead </h2> ...