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Re: PDF is only partially accessible

for

From: Geof Collis
Date: Dec 3, 2009 3:51PM

Hi Wayne

Would you be willing to let me put your words into an article and
post it to www.accessibilitynewsinternational.com ?

Email off list if you'd like and we can discuss.

cheers

Geof


At 05:13 PM 12/3/2009, you wrote:
>Accessibility of PDF
>
>Based on many of the responses from the WebAIM list, as well as from my
>own research, I conclude that well structured and tagged PDF is
>partially but not completely accessible. It excludes people with
>moderate low vision (20/70-20/160) from its accessibility supported
>group. See the American Optometric Association article on low vision for
>a complete classification of visual impairment from near normal vision
>to total blindness, http://www.aoa.org/low-vision.xml . I came to this
>conclusion with regret, because Adobe has been a model of corporate
>responsibility regarding accessibility support for several years.
>Still, I think PDF needs to go one more step to be classified as
>accessible without qualification.
>
>The group with moderate low vision needs a restyled page that can be
>read with their eyes. Alternative text is not useful for most of us.
>We can navigate documents with visual cues. Most of us use and like
>mice. In fact we can read and use almost everything but the body text.
> Tools like JAWS are an annoyance because unnecessary sound distracts
>us from the hard job of seeing with our limited vision. Zoom products
>are great for people with severe low vision, but they disrupt the space
>so much that we lose our visual ability to navigate using normal visual
>tools. What we need is enhanced text. That means size control that is
>not uniform for all tagged text types, e.g. paragraphs should be
>enlarged more than headings. We need clean and simple font families
>like Arial, Verdana or Tahoma. We also need spacing control over
>letters, words and lines. PDF does not seem to be able to provide these
>transformations.
>
>This is a direct deficit according to WCAG 2.0 Criteria 1.3.1. The less
>modern criteria of 508 1194.22(d) may let this slip by, but the intent
>of Section 504 and the ADA would consider this a deficit because it
>excludes a well defined disability group. Here is my analysis. Well
>structured and tagged PDF is not perceivable for people with moderate
>low vision at a level that facilitates effective use of print media for
>acquiring knowledge. This is because critical parts of well structured
>and tagged PDF documents are not adaptable to the needs of people with
>moderate low vision. Because WCAG 2.0 gives a direct analysis of why
>this is a problem I will use this standard. PDF fails to support
>Guideline 1.3, Criteria 1.3.1, Sufficient Technique G140.
>Adaptable:
>
>Guideline 1.3 Create content that can be presented in different ways
>(for example simpler layout ) without losing information or structure.
>Understanding Guideline 1.3 . PDF fails to support this Guideline
>because it fails to support 1.3.1 completely at the text level.
>Info and Relationships:
>
>Criterion 1.3.1 Information, structure, and relationships conveyed
>through presentation can be programmatically determined or are available
>in text. . PDF Fails this Criterion because text objects in PDF cannot
>be restyled visually an effective format for people with moderate low
>vision.
>
>Sufficient Technique G140: Separating information and structure from
>presentation to enable different presentations . -- Not supported
>completely by PDF.
>
>The text contents within paragraphs, lists and table cells appear to be
>immutable regarding the style properties: font family, spacing of
>letters, words and lines. That means the user cannot adjust necessary
>presentation style properties to support reading. This interferes with
>the person's ability to separate figure from ground.
>
>Serif fonts create a complex visual environment. Visual complexity is
>the enemy of people with low vision. Generally, people with moderate
>low vision benefit from a simple font line Arial, Helvetica and Tahoma.
> Choice of font family allows this group to use their limited sight
>effectively.
>Closely packed letters make reading long words difficult. The middle
>letters blur out. Closely packed words make separation of words
>difficult. Words can get blurred together and become unreadable, or
>they can disappear from sight. Closely packed lines make tracking
>difficult. One wanders from line to line in the middle of lines.
>
>Once again complexity is the problem. Separating text objects without
>sufficient spacing creates a difficult complex environment. Often
>publishers of large print books skimp on spacing and destroy the
>effectiveness of large print.
>
>Variable sizing is also critical. In a large print world with increased
>spacing, screen space is precious. Enlarging headings by the same
>factor as paragraph print is wasteful. There are many other cues that
>can designate the relative importance of text that do not require size.
> Borders, color for people who can see it, emphasis, strength and font
>style can all be used as visual level markers that can be used by this
>group and does not waste screen space.
>Accommodation vs. Accessibility
>
>There are accommodations and alternative media than can give a
>significantly inferior experience for this group. This is a well known
>fact because HTML and most Word Processing formats (doc, docx, rtf, odt)
>can product the exact formats that respect these needs of moderate low
>vision completely. So, objectively, PDF is not as accessible as word
>processing formats or HTML. From my point of view, life would be much
>better off if every posting in PDF was also posted in one of the
>completely accessible formats. Accessibility for reading documents
>means that the user with a disability can use a program to produce a
>format for reading that is just as usable as the format developed for
>the primary audience. Anything less is not completely accessible. That
>is why PDF is only partially accessible. People with moderate low
>vision cannot get an equally effective experience when they are forced
>to read PDF as their only choice. Unfortunately, large institutions
>have jumped on the notion that PDF can be made completely accessible,
>and the presence of stand-alone PDF postings is accelerating. This is a
>sad occurrence for those of us whose quality is directly reduced by this
>trend.
>What can Adobe and PDF Users Do
>
>Adobe needs to address this problem. They have addressed tagging,
>reading out loud, reflow, color, tables and most other problems. They
>can take one more step.
>
>Until this issue is resolved to the satisfaction of people with low
>vision, Adobe should not encourage the belief that their product can be
>made totally accessible.
>What can institutions do?
>
>Until Adobe completes its work with PDF to provide accessibility for all
>people with low vision, institutions should not engage in postings of
>stand-alone PDF. All postings of PDF documents should be accompanied by
>documents in a completely accessible format. Today we know these are
>obtained from word processors and W3C mark-up languages. TeX, LaTeX and
>MathML are good for mathematics. PDF is completely inaccessible for
>STEM publications.
>
>Wayne Dick PHD.
>California State University, Long Beach
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