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Re: Multiple Column Headers for one Column

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From: Steve Green
Date: Dec 19, 2019 1:54PM

The table can be theoretically accessible and can pass the relevant WCAG success criteria, but my experience is that it may not be accessible in practice. To some extent is depends on the number of columns and the amount of data in each header cell - the more of each, the less accessible the table will be in practice.

This has only come up in our user testing a couple of times, but all participants said the tables were incomprehensible even though they were marked up correctly. I just built a small table for testing, and the issues include:

1. When entering the table, the number of columns is announced. However, if the arrow keys are used to navigate linearly through the table, the colspans are not announced. If the user is counting the cells, they will misunderstand where they are in the table. They will also be unaware of the relationship between the multiple levels of headings. Almost all users navigate this way.

2. If the proper table navigation commands are used, none of those problems occur. However, in the tables I built, JAWS sometimes announces that the virtual focus is at the top of a column when it isn't, so you cannot navigate upwards to the cells above. You have to go sideways, then up, then sideways the opposite way. I have not fully diagnosed this, but it seems to happen with columns that do not contain a colspan. In my experience, almost no one uses the proper table navigation commands.

3. In Chrome, the column number for each cell is announced correctly, but in Internet Explorer they are not. For instance, if the first three cells on a row are in a colspan, the next cell is incorrectly announced as being in column 2. In Chrome, that cell is correctly announced as being in column 4. I have encountered tables where a cell was announced as being in different columns depending on how you navigated to it.

These behaviours occur with JAWS 2019, but my recollection is that these behaviours have been the same for at least 10 years, probably since the virtual object model was introduced in JAWS 7.10

Steve Green
Managing Director
Test Partners Ltd