W3C home > Mailing lists > Public > public-vocabs@w3.org > September 2013

Re: [a11y-metadata-project] Re: Schema.org accessibility proposal Review...

From: Andy Heath <andyheath@axelrod.plus.com>
Date: Sat, 07 Sep 2013 13:49:32 +0100
Message-ID: <522B20DC.8060600@axelrod.plus.com>
To: Charles McCathie Nevile <chaals@yandex-team.ru>
CC: "a11y-metadata-project@googlegroups.com" <a11y-metadata-project@googlegroups.com>, "<public-vocabs@w3.org>" <public-vocabs@w3.org>, Gerardo Capiel <gerardoc@benetech.org>, Dan Brickley <danbri@google.com>, Alexander Shubin <ajax@yandex-team.ru>, Egor Antonov <elderos@yandex-team.ru>, Liddy Nevile <liddy@sunriseresearch.org>, Charles Myers <charlesm@benetech.org>, Richard Schwerdtfeger <schwer@us.ibm.com>, George Kerscher <kerscher@montana.com>, Jason Johnson <jasjoh@microsoft.com>, Matt Garrish <matt.garrish@bell.net>

<Lots of snipping>

Chaals quoted (and wrote a little bit of):

>>> = accessMode =
>>
>>> It should be possible for a "single resource" to be available with
>>> more than one *set* of accessModes.
>>
>> I agree and this is the design.  A single resource can require one or
>> more accessMode(s).
>
> Yes, but...
>
>> … the accessMode property describes "Human sensory perceptual system
>> or cognitive faculty through which a person may process or perceive
>> information." […]
>> We have also published a best practices and an implementation guide on
>> the use of accessMode at:
>> <http://www.a11ymetadata.org/wp-content/uploads/2013/04/A11yMetadataProjectBestPracticesGuide_V.6.pdf>
>>
>> <https://wiki.benetech.org/display/a11ymetadata/Practical+Properties+Guide>
>>

Chaals wrote:

> Yep. But that has an example which I'll use:
>
> A movie with captions and extended audio description would be encoded as
> follows
> <div itemscope=”” itemtype=”http://schema.org/Movie”>
> <meta itemprop=”accessMode” content=”visual”/>
> <meta itemprop=”accessMode” content=”auditory”/>
> <meta itemprop=”mediaFeature” content=”audioDescription”/>
> <meta itemprop=”mediaFeature” content=”captions”/>
> </div>
>
> My first impression is that if the video has good audio description,
> then claiming it has accessMode "visual" seems wrong, since you don't
> need to see it. Likewise, since it is captioned, it seems you don't need
> to hear it.
>
> So it doesn't have a single *required* accessMode. On the other hand,
> you need to *either* see (clearly enough) or hear, in order to get the
> content.

The interpretation we had in AfA 3.0 of each property like this was that 
each specified not "accessMode required" but instead "accessMode 
available".  Did this project take a different interpretation ?

I haven't yet read the rest of this because I'm trying to focus on the 
same ISO meeting Chaals is in (but will do so) - this interpretation is 
so crucial as to change the whole emphasis so I wanted to reply quickly 
on this one point.

andy
axelrod access for all
DiversityNet
http://axelafa.com
>> accessMode is derived from the Access For All (AfA) specification...
>
>> We chose to leverage this prior work because
>> Schema.org<http://Schema.org> is meant to address search use cases,
>
> Yes, and I think that was the right choice. (Right now I am in an ISO
> meeting on this very topic).
>
>>> Essentially, it is unclear what accessMode really means. At least for
>>> the search use case where a user needs to find a suitable resource, I
>>> think the only way this can really work is if an accessMode is a set
>>> of one or more *required user capabilities*.
>>
>> Yes, I think that is what we are saying too.  In fact, it seems like
>> what others have understood on the public vocabs list as evidenced by:
>> http://lists.w3.org/Archives/Public/public-vocabs/2013May/0092.html
>
> Not quite. The example there suggests (based on the documentation of
> what accessMode means) that you need both visual and tactile
> interactivity to work with the resource.
>
> But I agree that what people understand in the examples quoted is that
> there are multiple ways to access some things.
>
>> http://lists.w3.org/Archives/Public/public-schemabibex/2013Aug/0049.html
>
> I'll leave Karen to answer on that one…
>
>>> To pick some examples:
>>
>>> Alice In Wonderland is available as a resource which only *requires*
>>> the ability to read text.
>>
>> We happen to have a few versions of Alice in Wonderland in Bookshare
>
> Yep.
>
>> If you inspect one of those titles using Yandex's webmaster tools or
>> Google's rich snippets tool that lets me just plug in a URL parameter,
>> we can see the accessibility microdata on that page:
>> http://www.google.com/webmasters/tools/richsnippets?q=https%3A%2F%2Fwww.bookshare.org%2Fbrowse%2Fbook%2F18041<http://www.google.com/webmasters/tools/richsnippets?q=https://www.bookshare.org/browse/book/18041>
>>
>
> I looked at https://www.bookshare.org/browse/book/268061 with
> http://webmaster.yandex.ru/microtest.xml
>
>> As you can see we offer 4 different adaptations of that title, which
>> we originally adapted from a physical book that we scanned.  For each
>> adaptation we describe the accessModes that are used.
>
> Yes. But
> <https://www.bookshare.org/download/book?titleInstanceId=268061&downloadFormat=DAISY_WITH_IMAGES>
> doesn't actually *require* visual capability, does it?
>
> [...]
>>> If there is a movie of Alice In Wonderland available with captions,
>>> then there are two sets of requirements. One is to be able to watch a
>>> movie and listen to the audio, and the second set is to be able to
>>> watch a movie and read the captions. (If it had descriptive audio, a
>>> third would be being able to hear the descriptive audio and the main
>>> audio…)
>
> (See also the movie example mentioned earlier)
>
>> That is the purpose of mediaFeature.  A movie typically has
>> accessModes of visual and auditory.  If it has captions, we simply add
>> a mediaFeature of captions and/or a mediaFeature of audioDescription.
>> You can find an example in our Practical Properties Guide:
>>
>> https://wiki.benetech.org/display/a11ymetadata/Practical+Properties+Guide#PracticalPropertiesGuide-Video
>>
>
> Yes, but I don't think that is actually correct. If the movie has
> captions, you *don't* necessarily need auditory capacity anymore.
> However, in order to watch the movie without auditory capability, you
> may need the ability to read images of text (this also depends on the
> format used for captioning...)
>
>>> It might be that this assumption is already made in the proposal,
>
> It certainly seems to be an assumption.
>
>>> but it is not explicit, and the proposal doesn't explain how to deal
>>> with a single version that can be used with different sets of
>>> capabilities (whereas it includes a way to point to other versions)
>
>> Schema.org<http://Schema.org> allows for multiple values for the same
>> property.  For example, take a look at the example properties for
>> ingredients at the bottom of this page: http://schema.org/Recipe
>
> Sure. But while the data about Alice in Wonderland shows how to include
> multiple alternative books, each with a *set* or properties, I am not
> sure the accessMode definition works for including different
> combinations that are "mutually exclusive".
>
> To continue the captioned, audio described movie example, I think we
> should be saying it has an accessMode which requires the ability to see
> and hear, a different accessMode that requires the ability to hear, and
> a third one that requires the ability to see and to read text on images.
>
> Any *one* of these is sufficient for a user to successfully use the
> video resource, no?
>
>>> == details in accessMode ==
>>
>>> the top-level accessMode is only useful for "most" cases. Knowing
>>> that I am physically capable of watching and listening to a video is
>>> great, unless it is only available in a format I cannot use such as
>>> "flash for my iPhone 3", "ogg theora/vorbis"….
>>
>> Schema.org<http://Schema.org> already has a properties for formats
>> (e.g., http://schema.org/encodingFormat ,
>> http://schema.org/BookFormatType )
>
> Yep. So we should be expecting those to be used, right?
>
>>> Similarly if I have more detailed requirements. For example although
>>> I can watch and hear a video tutorial, being red-green colourblind or
>>> requiring very high contrast may mean I can't actually understand it
>>> in practice.
>>
>> For those use cases, we have accessMode = colorDependent
>
> Yes. But this assumes that users who require white-on-black, users who
> use a common high-contrast mode, and users who are unable to distinguish
> light blue from white have the same requirements.
>
>> and mediaFeature =
>
> Something missing here.
>
>> = accessFeature =
>
>>> Are these just cataloguing information, similar to noting that a
>>> physical book has 5 pages of color photographs, or a guarantee that
>>> e.g. each image has alternative text, or a longer description is
>>> provided as necessary?
>>
>> We thought that implementing AfA or ISO 24751 verbatim for the
>> purposes of web search and for use by web masters would be too
>> complicated: it needed to be a small set of properties that a user
>> could deal with.
>
> Hmmm. It needs to be as simple as possible - and no simpler...
>
>> We decided to combine various ideas into mediaFeature.
>
> Which I think makes sense.
>
>> mediaFeature simply states that the author/publisher or someone who
>> modified that book, tried to take advantage the stated accessibility
>> features.
>
> Right.
>
>> For example we make no promise that every image was described
>> appropriately,
>
> But is best practice to use mediaFeature: textAlternative when there is
> at least one image with an alternative, or when all the images have one?
>
> (We can't guarantee that everyone does everything perfectly, but it is
> important to explain what we think people should be trying to do as well
> as they can).
>
>>> It isn't clear, for example, how to classify a resource that assumes
>>> the ability to touch several points of a screen at once, which is now
>>> a common feature on devices but poses an obvious potential problem to
>>> some users such as those who don't have very many fingers.
>>
>> In this use case, the resource that needs to be described is an
>> application, not the content.
>
> Hmm. I don't understand the difference between applications and content.
> I can see there are some things I would call one, and some that I would
> call the other, but resources identified by schema.org seem hard to
> classify into one or the other.
>
> For example, is an interactive map an application or content? What about
> a document that allows structured navigation, a la DAISY?
>
> I don't know of a clear way to determine the difference. But then, I am
> not convinced that we need one.
>
>> If the accessibility API of this application supports multi-touch with
>> the user’s AT, then the proposed ATCompatible and accessAPI properties
>> should be relevant. Furthermore, we also have a property called
>> controlFlexibility, which also should provide information about whether
>> the application can be fully controlled either via audio, mouse,
>> keyboard, touch or video/gestures.
>
> Yes.
>
>>> = adaptations, other versions, ... =
>>>
>>> Liddy has pointed out that the concept of "the original" is only
>>> sometimes interesting, and that it isn't an accessibility concept but
>>> a more general one related to creative works.
>>
>> Actually to a teacher, the “original” is important if they are trying
>> to find a resource for a disabled student that is an adaptation of the
>> “original” resource used by the rest of the students in the classroom
>> who don’t have a disability.
>
> I don't think so, I believe they are happy to know that two things are
> versions of each other without caring which was the original.
>
>> Similarly a publisher or book seller wants to make it easy for consumers
>> with specialized needs to find resources that have been adapted or “made
>> accessible.”
>
> But again, the publisher doesn't really care which is the "original" -
> and in the case of modern electronic works, the concept may not have a
> real meaning.
>
>> These adaptations properties are also derived from AfA and
>> ISO 24751 and I think it’s worthwhile reading their specifications to
>> understand their reasoning. We did simplify the terms (removing partial
>> adaptation and the like) to simplify this for search purposes.
>
> There is a lot of literature, and there are a number of standards,
> describing how instances of a CreativeWork relate to each other. I don't
> think we *need*, for accessibility, anything more than the super-simple
> "this is a version of that". If people need to describe the relationship
> for other reasons, they should use something that can support the things
> they may need - i.e. the stuff that got removed (and probably stuff that
> was never in AfA but is in Bibex, or FRBR…)
>
>>> This isn't high priority, except that I think we should quickly
>>> decide we want to avoid dealing with defining stuff that others have
>>> spent decades on, and instead try to use their work...
>
> This isn't high priority, except that I think we should quickly decide
> we want to avoid dealing with defining stuff that others have spent
> decades on, and instead try to use their work...
>
>>> = ATCompatible =
>>
>>> being a boolean seems a bit naive. I can think of lots of resources
>>> that work with specific assistive technologies, but fail with others
>>> (my instant example is http://cookiecrook.com/longdesc/iframe/ which
>>> works great on VoiceOver but as far as I can tell does nothing to
>>> work effectively with the built-in MacOS magnifier - two assistive
>>> technologies I have readily available…).
>>
>> In the case of content, we once again, we tried to simplify the work
>> for web masters and searchers. Since we can always expand the vocabulary,
>
> This is why I think fixing this bit is not the first priority.
>
>> we decided to err on simplicity, and to just have the focus on whether
>> accessible technology was considered;
>
> Yes, but
>
>> enumerating WCAG sections would be overly daunting in a search.
>
> Well, it would be a fairly unfriendly way to define things.
>
>> In the case of applications, we did provide greater granularity with the
>> accessAPI property, which would differentiate what accessibility API,
>> such as VoiceOver, the application is compatible with.
>
> Yes. Because for an actual user, it doesn't matter that the developer
> considered assistive technology in general, only whether they can use a
> resource with their particular setup. This is analagous to the reason
> why knowing the format of a resource is important.
>
>> I don't think ATCompatible is the first priority for fixing. But I do
>> think it should be replaced with something because I don't think it is
>> very useful.
>>
>>> = Evolution =
>>
>>> Who looks after the terms, and how do they get extended?
>>
>> This is probably the problem with any Schema.org<http://Schema.org>
>> proposal.
>
> Sure. Which is why I ask the question in this particular case :)
>
>>  By basing this proposal on existing standards, such as AfA and ISO
>> 24751, it will be easier to evolve these terms as more people and
>> organizations (e.g., IMS, GPII, IDPF) will be invested in keeping
>> these terms synchronized with other standards and technologies.
>
> My experience suggests that this will actually make it harderif the
> different standards aren't already evolving in lock-step, unless we have
> a clear story for what triggers changes in the schema.org version.
>
>> We believe that there are some efforts with 24751 to have a registry
>> to assist in this process.
>
> There are efforts in 24751 to have a registry, but I am not sure that
> its purpose is to facilitate keeping schema.org as useful as possible in
> the face of the evolving world.
>




andy
andyheath@axelrod.plus.com
-- 
__________________
Andy Heath
http://axelafa.com
Received on Saturday, 7 September 2013 12:50:03 UTC

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