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Re: data or layout table

for

From: Jared Smith
Date: Sep 2, 2011 9:51AM

On Fri, Sep 2, 2011 at 9:20 AM, Duff Johnson wrote:

> Accordingly the need for table headers in HTML (and elsewhere), it seems to me, is a function of whether or not headers are logically present in the table, period.

I agree that this is almost always the case. But sometimes data is
presented in a table in a way that makes sense visually, but when
accessed by a screen reader could be very confusing. In such cases,
adding headers (even perhaps keeping them hidden) might be best for
accessibility.

Consider Deborah's example of images, links, and a bit of information
presented in a table. It would make sense to a screen reader reader
user if the information is read left to right through rows as...
Image, link, info.
Image, link, info.
etc...

This would be little different than presenting them without a table
layout. Adding headers would just add overhead that is not necessary.

However, if the logical reading order is...
Image, image, image.
Link, link, link.
info, info, info.
etc...

... this would quickly become very difficult to comprehend linearly in
a screen reader, yet would still make perfect sense visually. The
presentation of each column visually (e.g., a column of image
thumbnails of quilt squares) presents information that a screen reader
user would not easily get. In this case, the addition of a column
header would greatly improve accessibility.

Hopefully that makes sense.

Jared