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Number of posts in this thread: 14 (In chronological order)

From: LSnider
Date: Sun, Aug 21 2011 12:00PM
Subject: PDFs and NVDA
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Hello Everyone,

I have always tagged PDFs, but I know there is a lot more one can do to make
them accessible. I am doing a lot of work on accessible PDFs right now and
have a question.

I did a test document from Word, and used the proper heading structure. I
made a PDF of it and then tagged it in Acrobat. I am a sighted viewer but
use NVDA as a screen reader (JAWS killed my computer a couple of months
back, must have been a video driver issue).

I assumed that NVDA would be able to list the headings, but that didn't
happen-it was just a blank list (even though I did them properly in word).
So I changed the reading options in Acrobat from infer reading order in
document to tagged reading order and then NVDA happily gave me the list of
headings.

For those of you who use NVDA or JAWS, all the time, when you read PDFs do
you need Acrobat/Reader to be set to tagged reading order? If this is the
case, then what happens when there are no tags? Is it a total mess of
confusion?

Cheers and thanks for your advice in advance.

Lisa

From: Duff Johnson
Date: Sun, Aug 21 2011 12:27PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

> I assumed that NVDA would be able to list the headings, but that didn't
> happen-it was just a blank list (even though I did them properly in word).
> So I changed the reading options in Acrobat from infer reading order in
> document to tagged reading order and then NVDA happily gave me the list of
> headings.

Yes. Heading structure may be found in the tags. In PDF, there's no other proper place to look for it (I'm leaving aside a technically available but nonetheless pointless option).

> For those of you who use NVDA or JAWS, all the time, when you read PDFs do
> you need Acrobat/Reader to be set to tagged reading order?

Since tags are the only place in which to find the file's logical structure (sequence, nesting and semantics), yes, you need Acrobat/Reader/3rd party option to use the "tagged reading order".

> If this is the
> case, then what happens when there are no tags? Is it a total mess of
> confusion?

Tags are essential to accessible PDF, period. The only exception (in a purely operational sense) would be a document that is so simple that it's possible to have the raw print stream (thanks Karen!) just happen to match the document's logical structure.

As such, there is no "rule' about what to do in the absence of tags - there are merely a couple of options, both of them bad.

In the case of an untagged PDF, applications can either (a) follow the raw print stream or (b) possess the smarts to analyze the page layout and make choices that override the as-printed sequence.

An untagged PDF - even if all the content just happens to occur in correct reading order - is semantically equivalent to a single giant <P> tag containing all the text in the PDF - unacceptable for accessibility purposes.

I hope this helps.

Duff Johnson

p +1.617.283.4226
e = EMAIL ADDRESS REMOVED =
t http://www.twitter.com/duffjohnson
w http://www.duff-johnson.com

From: LSnider
Date: Sun, Aug 21 2011 1:21PM
Subject: Re: PDFs and NVDA
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Hi Duff,

Thanks for your answers, much appreciated. So a few follow up questions:

-If most people use the tagged reading order, what are the uses for the
other reading orders in Acrobat/Reader?

-If I don't use proper headers in a Word doc (which will be made into the
PDF), the tagging can't tell what is a header, correct? It just guesses? To
me with my testing, it seems like it guesses and I think that is what you
said below, but just wanted to confirm.

-The touchup reading order in Acrobat can be used to tweak what the tagging
does? I haven't used that one a lot before...I usually try to make well
structured documents in Word and they usually come out okay, but maybe I
should be using that touchup tool..

Thanks again, this is very helpful.

Cheers

Lisa


On Sun, Aug 21, 2011 at 11:26 AM, Duff Johnson < = EMAIL ADDRESS REMOVED = >wrote:

> Yes. Heading structure may be found in the tags. In PDF, there's no other
> proper place to look for it (I'm leaving aside a technically available but
> nonetheless pointless option).
>
> Since tags are the only place in which to find the file's logical structure
> (sequence, nesting and semantics), yes, you need Acrobat/Reader/3rd party
> option to use the "tagged reading order".
>
> Tags are essential to accessible PDF, period. The only exception (in a
> purely operational sense) would be a document that is so simple that it's
> possible to have the raw print stream (thanks Karen!) just happen to match
> the document's logical structure.
>
> As such, there is no "rule' about what to do in the absence of tags - there
> are merely a couple of options, both of them bad.
>
> In the case of an untagged PDF, applications can either (a) follow the raw
> print stream or (b) possess the smarts to analyze the page layout and make
> choices that override the as-printed sequence.
>
> An untagged PDF - even if all the content just happens to occur in correct
> reading order - is semantically equivalent to a single giant <P> tag
> containing all the text in the PDF - unacceptable for accessibility
> purposes.
>
> I hope this helps.
>
> Duff Johnson
>
>

From: Bevi Chagnon
Date: Sun, Aug 21 2011 2:57PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

Lisa, I think you mean "headings" not "headers."
They are very different parts of a page.
To help understand the difference: when you think of a header also think of
its mate, a footer. Headers are running headers (aka page numbers, folios,
repeating info) that repeat at the top of every page.

A heading is a headline, subhead, title or something similar that is part of
the body text on a page. Headings are used by assistive technologies for
quick navigation while headers are usually ignored.

Similar usage for tables. A table header is the repeating information at the
top and includes the column heads. A table heading falls in within the body
of the table and acts like a subhead, dividing one portion of a table from
another.
In tables, the header is used by assistive technologies to orientate the
user, while table headings (subheads) are usually read like any other text
in the table and often confuse the heck out of AT users.

--Bevi Chagnon
(former editor and typesetting)

--
Bevi Chagnon | = EMAIL ADDRESS REMOVED =
PubCom - Trainers, consultants, designers, and developers
Print, Web, Acrobat, XML, eBooks, and Federal Section 508
--
* It's our 30th Year! *

From: Karlen Communications
Date: Sun, Aug 21 2011 3:30PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

I wrote an article on the Karlen Communications blog called "Headings, Headers, Headaches" to help explain the difference between heading styles, page headers and table headers...hence the "headache" part when you are learning the differences.

Http://www.karlencommunicatns.com/Blog

Cheers, Karen

Out of Office, Sent from my iPad

On 2011-08-21, at 4:57 PM, "Bevi Chagnon" < = EMAIL ADDRESS REMOVED = > wrote:

> Lisa, I think you mean "headings" not "headers."
> They are very different parts of a page.
> To help understand the difference: when you think of a header also think of
> its mate, a footer. Headers are running headers (aka page numbers, folios,
> repeating info) that repeat at the top of every page.
>
> A heading is a headline, subhead, title or something similar that is part of
> the body text on a page. Headings are used by assistive technologies for
> quick navigation while headers are usually ignored.
>
> Similar usage for tables. A table header is the repeating information at the
> top and includes the column heads. A table heading falls in within the body
> of the table and acts like a subhead, dividing one portion of a table from
> another.
> In tables, the header is used by assistive technologies to orientate the
> user, while table headings (subheads) are usually read like any other text
> in the table and often confuse the heck out of AT users.
>
> --Bevi Chagnon
> (former editor and typesetting)
>
> --
> Bevi Chagnon | = EMAIL ADDRESS REMOVED =
> PubCom - Trainers, consultants, designers, and developers
> Print, Web, Acrobat, XML, eBooks, and Federal Section 508
> --
> * It's our 30th Year! *
>
>
>

From: Duff Johnson
Date: Sun, Aug 21 2011 3:45PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

Lisa,

First, Bevi is correct in her comments.

I'm going to make a couple of similarly pedantic-seeming points :-)

> -If most people use the tagged reading order, what are the uses for the
> other reading orders in Acrobat/Reader?

It's not that "most people" use the tagged reading order... it's that tags are the ONLY place for logical structure, which is vital to the reliable reading and navigation of a PDF using AT. That said, many (most) applications OTHER than Adobe's are unable (at this time) to create or process tags in a PDF. Microsoft Office supports tagged PDF generation from Word files, and so does Open Office.

> -If I don't use proper headers in a Word doc (which will be made into the
> PDF), the tagging can't tell what is a header, correct?

Key point: The tags COME FROM the headings (not "headers", per Bevi). Software that supports creation of accessible PDFs from the source file will convert the structures present in the source file into corresponding PDF tags. So, exactly as you surmise... use good structures in your source file, and you have the right to expect a matching structure in your PDF.

> It just guesses? To
> me with my testing, it seems like it guesses and I think that is what you
> said below, but just wanted to confirm.

PDFs generated by software that does not support tagged PDF for output may be handled for accessibility purposes in two basic ways.

1) The "raw print stream" (PDF name is "reading order" - see earlier threads). In practice, this is what most software reads instead of the tags. The results range from "so-so" on extremely simple documents to "chaotic" in other cases.

2) Some interpretation of the raw print stream using other information (page-position, font size, font choice, etc, etc).

It should be noted that both of the above approaches are totally illegitimate with respect to accessibility. There is only one option that can comply with WCAG 2.0 - support for tagged PDF in all its particulars. Yes... some users get good use from software that (primarily) uses reading order (cell phones, for example), but that's simply an example of something being better than nothing.

> -The touchup reading order in Acrobat can be used to tweak what the tagging
> does?

That tool tweaks BOTH the raw print stream order (content order) AND the tag order. While this is not an unreasonable thing to do in the right circumstances, execution is everything, and I do not recommend the use of this tool in its current manifestation for this purpose.

> I haven't used that one a lot before...I usually try to make well
> structured documents in Word and they usually come out okay, but maybe I
> should be using that touchup tool..

The first part... focus on getting the source file as good as possible so that tweaking in Acrobat or with other tools is minimized... is exactly correct.

Otherwise... all the fixup following file creation can generally be done in the tags panel. Some of the Touch Up Reading Order Tool elements can be handy, but it's not a great tool, sorry to say.

Duff Johnson

p +1.617.283.4226
e = EMAIL ADDRESS REMOVED =
t http://www.twitter.com/duffjohnson
w http://www.duff-johnson.com

From: LSnider
Date: Sun, Aug 21 2011 5:42PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

Hi Bevi,

Yes, headings! I havve been making that error all weekend, argh! I know the
difference but for some reason my brain keeps thinking headers. I meant
headings :)

Cheers

Lisa

On Sun, Aug 21, 2011 at 1:57 PM, Bevi Chagnon < = EMAIL ADDRESS REMOVED = > wrote:

> Lisa, I think you mean "headings" not "headers."
> They are very different parts of a page.
> To help understand the difference: when you think of a header also think
> of
> its mate, a footer. Headers are running headers (aka page numbers, folios,
> repeating info) that repeat at the top of every page.
>
> A heading is a headline, subhead, title or something similar that is part
> of
> the body text on a page. Headings are used by assistive technologies for
> quick navigation while headers are usually ignored.
>
> Similar usage for tables. A table header is the repeating information at
> the
> top and includes the column heads. A table heading falls in within the body
> of the table and acts like a subhead, dividing one portion of a table from
> another.
> In tables, the header is used by assistive technologies to orientate the
> user, while table headings (subheads) are usually read like any other text
> in the table and often confuse the heck out of AT users.
>
> --Bevi Chagnon
> (former editor and typesetting)
>
>

From: LSnider
Date: Sun, Aug 21 2011 5:48PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

Hi Karen,

It is so weird, I have never confused the two in 12 years and all of a
sudden my brain replaces headers for headings...weird!

Heading styles is what I meant, now if my fingers would only type that!

Cheers

Lisa

On Sun, Aug 21, 2011 at 2:32 PM, Karlen Communications <
= EMAIL ADDRESS REMOVED = > wrote:

> I wrote an article on the Karlen Communications blog called "Headings,
> Headers, Headaches" to help explain the difference between heading styles,
> page headers and table headers...hence the "headache" part when you are
> learning the differences.
>
> Http://www.karlencommunicatns.com/Blog
>
> Cheers, Karen
>
>

From: LSnider
Date: Sun, Aug 21 2011 5:54PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

Hi Duff,

Yes, headings was correct LOL.

I asked about the reading order differences in Acrobat/Reader because I
always thought there was a default reading order that would help screen
readers. What confused me was that I had to set it to tabbed reading order
in my version of Acrobat, as it wasn't the default for my Acrobat 9 program.
It seems like it would be better to have that as the program default, but I
am sure there is a reason why it was done that way.

I hadn't realized that about other PDF programs, good to know. I have used
Acrobat since it was created and always liked it best, so I don't use the
others much unless a client asks for it.

Yes I played with Word a lot over the years and in 2007 (I am going to
install 2010 next week) I like the fact that you can create PDFs that are
already tagged, nice feature.

Okay, that is what I thought about the tagging, so thanks for confirming
that for me.

Very good reasons for tagging, and thanks for the information on the touch
up tool. I strive for good source documents, so good to know that is the way
to go.

Thanks again!

Cheers

Lisa

On Sun, Aug 21, 2011 at 2:42 PM, Duff Johnson < = EMAIL ADDRESS REMOVED = > wrote:

It's not that "most people" use the tagged reading order... it's that tags
> are the ONLY place for logical structure, which is vital to the reliable
> reading and navigation of a PDF using AT. That said, many (most)
> applications OTHER than Adobe's are unable (at this time) to create or
> process tags in a PDF. Microsoft Office supports tagged PDF generation from
> Word files, and so does Open Office.
>
> Key point: The tags COME FROM the headings (not "headers", per Bevi).
> Software that supports creation of accessible PDFs from the source file will
> convert the structures present in the source file into corresponding PDF
> tags. So, exactly as you surmise... use good structures in your source file,
> and you have the right to expect a matching structure in your PDF.
>
> PDFs generated by software that does not support tagged PDF for output may
> be handled for accessibility purposes in two basic ways.
>
> 1) The "raw print stream" (PDF name is "reading order" - see earlier
> threads). In practice, this is what most software reads instead of the tags.
> The results range from "so-so" on extremely simple documents to "chaotic" in
> other cases.
>
> 2) Some interpretation of the raw print stream using other information
> (page-position, font size, font choice, etc, etc).
>
> It should be noted that both of the above approaches are totally
> illegitimate with respect to accessibility. There is only one option that
> can comply with WCAG 2.0 - support for tagged PDF in all its particulars.
> Yes... some users get good use from software that (primarily) uses reading
> order (cell phones, for example), but that's simply an example of something
> being better than nothing.
>
> That tool tweaks BOTH the raw print stream order (content order) AND the
> tag order. While this is not an unreasonable thing to do in the right
> circumstances, execution is everything, and I do not recommend the use of
> this tool in its current manifestation for this purpose.
>
> The first part... focus on getting the source file as good as possible so
> that tweaking in Acrobat or with other tools is minimized... is exactly
> correct.
>
> Otherwise... all the fixup following file creation can generally be done in
> the tags panel. Some of the Touch Up Reading Order Tool elements can be
> handy, but it's not a great tool, sorry to say.
>
> Duff Johnson
>
> p +1.617.283.4226
> e = EMAIL ADDRESS REMOVED =
> t http://www.twitter.com/duffjohnson
> w http://www.duff-johnson.com
>
>

From: Karlen Communications
Date: Mon, Aug 22 2011 6:12AM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

OK, found the NVDA keyboard command and headings are being listed in my PDF
documents. Can you send me the sample Word and PDF documents to look at off
list?

Cheers, Karen

From: Karlen Communications
Date: Mon, Aug 22 2011 6:18AM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

The recommended "reading order" is to infer the reading order from the
document. This is what Acrobat or Reader should be set at by default in the
Reading category of the Preferences. Tab Order only comes into play for
forms or PDF documents with links. This is the only time we have the option
to "Tab" through content and the content being tabbed through are the form
controls and the links not the "regular text" of the document. Any document
without links or form controls we use standard navigation/reading keyboard
commands for moving through documents.

The other two options, left to right, top to bottom and the raw print
stream are used for legacy or untagged PDF documents and are meant to be an
option in getting some kind of sense out of the document when the
recommended reading order doesn't work with the PDF. These are options even
if the PDF is tagged but not tagged properly. Duff is correct in that Tags
are what makes a PDF accessible and these other two options are considered
to be last resorts when the document is not tagged...or as I've said, not
tagged correctly.

I have NVDA and opened a PDF tagged from Word in Acrobat 9. When I press H
NVDA does move from heading to heading in the document. I couldn't find
reference to the keyboard command to list headings in NVDA...am a JAWS user.
Can you send the keyboard command and I'll see if it works with my
documents? My first thought was that NVDA didn't have this feature for PDF
documents which is why you got an empty list or no list at all. I did try to
find a list of the keyboard commands for NVDA but the WebAIM link which
seems to be the best match to the search results won't open and all other
references don't mention listing headings as a feature of NVDA. Will keep
trying but if you have the keyboard command that would be helpful.

Cheers, Karen

From: Tania
Date: Tue, Aug 23 2011 8:36PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

NVDA KEYBOARD COMMANDS:
on the numpad, the NVDA key as same as jaws key.
Press: nvda + n
To bring up nvda menu. arrow down to 'help'. arrow right then down to quick
keyboard commands.
cheers
tania



----- Original Message -----
From: "Karlen Communications" < = EMAIL ADDRESS REMOVED = >
To: "'WebAIM Discussion List'" < = EMAIL ADDRESS REMOVED = >
Sent: Monday, August 22, 2011 6:32 PM
Subject: Re: [WebAIM] PDFs and NVDA


> Th

From: LSnider
Date: Wed, Aug 31 2011 2:30PM
Subject: Re: PDFs and NVDA
← Previous message | Next message →

Hi Karen,

My apologies for the delay, I was at a conference for 8 days.

Thanks, that was great information.

Webaim has a great list of NVDA shortcuts, it was very helpful for me when I
was putting together a presentation. They have JAWS shortcuts too. Being a
sighted user, I need to play with them more.

Cheers and thanks again,

Lisa

On Mon, Aug 22, 2011 at 3:32 AM, Karlen Communications <
= EMAIL ADDRESS REMOVED = > wrote:

> The recommended "reading order" is to infer the reading order from the
> document. This is what Acrobat or Reader should be set at by default in the
> Reading category of the Preferences. Tab Order only comes into play for
> forms or PDF documents with links. This is the only time we have the option
> to "Tab" through content and the content being tabbed through are the form
> controls and the links not the "regular text" of the document. Any document
> without links or form controls we use standard navigation/reading keyboard
> commands for moving through documents.
>
> The other two options, left to right, top to bottom and the raw print
> stream are used for legacy or untagged PDF documents and are meant to be an
> option in getting some kind of sense out of the document when the
> recommended reading order doesn't work with the PDF. These are options even
> if the PDF is tagged but not tagged properly. Duff is correct in that Tags
> are what makes a PDF accessible and these other two options are considered
> to be last resorts when the document is not tagged...or as I've said, not
> tagged correctly.
>
> I have NVDA and opened a PDF tagged from Word in Acrobat 9. When I press H
> NVDA does move from heading to heading in the document. I couldn't find
> reference to the keyboard command to list headings in NVDA...am a JAWS
> user.
> Can you send the keyboard command and I'll see if it works with my
> documents? My first thought was that NVDA didn't have this feature for PDF
> documents which is why you got an empty list or no list at all. I did try
> to
> find a list of the keyboard commands for NVDA but the WebAIM link which
> seems to be the best match to the search results won't open and all other
> references don't mention listing headings as a feature of NVDA. Will keep
> trying but if you have the keyboard command that would be helpful.
>
> Cheers, Karen
>

From: LSnider
Date: Wed, Aug 31 2011 2:36PM
Subject: Re: PDFs and NVDA
← Previous message | No next message

Hi Karen,

I deleted that file! Argh, sorry about that one. If I find another example,
then I will send it to you off list.

Cheers

Lisa

On Mon, Aug 22, 2011 at 3:42 AM, Karlen Communications <
= EMAIL ADDRESS REMOVED = > wrote:

> OK, found the NVDA keyboard command and headings are being listed in my PDF
> documents. Can you send me the sample Word and PDF documents to look at off
> list?
>
> Cheers, Karen
>
>
>