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Re: Complex "Rule" table in PDF

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From: Steve Green
Date: Aug 19, 2009 11:05AM

From: Langum, Michael J [mailto: <EMAIL REMOVED> ]
Sent: Wednesday, August 19, 2009 11:48 AM
To: Duff Johnson; <EMAIL REMOVED> ; Andrew Kirkpatrick; Don
Barrett; <EMAIL REMOVED>
Subject: Complex "Rule" table in PDF

You guys are my "go to" people for difficult PDF/accessibility issues. If
anyone has time, I'd really appreciate some help on this.


I have been given a large document with many complex rule tables like this:
http://www.opm.gov/_mike/test/PDF-Issues/BadTableExample.pdf.

You'll notice that the "IF" part of the rules covers columns 2 - 4, and the
"THEN" part of the rules covers columns 5 - 8.

Also, in many cases, cells span multiple rows.

What is the best way to work with this in PDF tagging?

I'm sure I can't simply make all the cells in the first column be <th> and
add "scope=row".

Would it be enough to make all the cells in the "IF" columns be <th> and add
"scope=row"?

Do I need to explicitly copy and paste the contents of all the related "IF"
cells, into the "alternate text" for each cell in the "THEN" cells?

Are there reasonable alternatives?
-- Mike

________________


Mike,

Would I be correct in assuming that you are primarily concerned with screen
reader users (they are the main beneficiaries of semantic markup of this
nature)? In my experience the table will be virtually incomprehensible even
if marked up correctly.

Data tables are difficult enough to comprehend and navigate, but colspans
and rowspans complicate matters massively. This is because screen readers
are unable to inform the user about the colspans and rowspans, and the same
spanned cell can appear to have different row or column numbers depending on
how you navigate to it. Even the most proficient users struggle (and often
fail) to understand tables like this.

My recommendation would be to eliminate the colspans and rowspans and repeat
the data where necessary. It may look unusual but it will be far more
comprehensible.

Steve Green
Director
Test Partners Ltd