- From: David MacDonald <david100@sympatico.ca>
- Date: Thu, 29 Oct 2015 05:17:13 -0400
- To: Can Wang <wcan@zju.edu.cn>
- Cc: Gregg Vanderheiden RTF <gregg@raisingthefloor.org>, Detlev Fischer <detlev.fischer@testkreis.de>, "lisa.seeman" <lisa.seeman@zoho.com>, GLWAI Guidelines WG org <w3c-wai-gl@w3.org>
- Message-ID: <CAAdDpDbbSRvomjHH-c5VLnSHZAOrO9gkwoYCUHeT8uNrwXUysg@mail.gmail.com>
Hi Can We cannot test all of WCAG with automation, only about 15-30% can be tested via automation. We need human intervention. For large sites it is prohibitively expensive. However, we have laid out recommendations on how to sample pages and test a limited group of pages on a site in the Evaluation Methodology. http://www.w3.org/TR/WCAG-EM/ Cheers, David MacDonald *Can**Adapt* *Solutions Inc.* Tel: 613.235.4902 LinkedIn <http://www.linkedin.com/in/davidmacdonald100> www.Can-Adapt.com * Adapting the web to all users* * Including those with disabilities* If you are not the intended recipient, please review our privacy policy <http://www.davidmacd.com/disclaimer.html> On Wed, Oct 28, 2015 at 8:39 PM, Can Wang <wcan@zju.edu.cn> wrote: > Actually that SC says the alternate text shall serve the same purpose as > the non-test content. I know it might seem inappropriate to pop up this > question here. But this SC is not as easily tested as one might imagine. It > is easy to have one person check the alt text for an image and tell whether > the description matches the image. But it is difficult to automate this > test. I mean have it done by a computer program. There was a website we > once tested in China, with most of images on its pages captions as "This is > an image". If you think the semantics of images are important, this alt > text shall not pass the SC. > > We have encountered many similar issues in accessibility evaluation for > websites in China. There are huge amount of pages in a site and human > inspection is prohibitively expensive. So the evaluation must be automated. > But in this sense, you find that many SCs are not easily TESTABLE. Shall be > consider the easiness for automating the tests in the future? > > Can Wang > > 发自我的 iPhone > > 在 2015年10月29日,08:41,Gregg Vanderheiden RTF <gregg@raisingthefloor.org> 写道: > > Hmmm > not quite > > > For example and SC that says there must be alternate text (that is > accessibility supported) is very testable. There are many ways to do it > — so no one thing is deterministic. But it is very easy to test if it is > there in a manner that works with screen readers — by just using a screen > reader. > > The question isnt whether one particular technique is deterministic but > whether it can be test (automatically or by humans) in a reliable way. > > > Another I that contrast must be X. There are many techniques for > ensuring this — but if it is true, it is true. > > > So the question of whether something can be ANY KIND Of criteria — is > whether you can tell when you have met it. Success criteria are no > different (if we want to use the english definition of criteria).. > > To be a criteria - it must be possible to know if you have met it. That > is, it must be testable in a way that you get a reliable, repeatable, > consistent result when tested by different people. > > And if the criteria is to apply to all content — then it must be possible > (and reasonable) and testable for all content. > > Bringing up techniques only muddies the water. You can pass a technique > and fail the SC (if there is other content on the page using another > technology for example). You can also fail a technique and pass the SC (if > you met it another way). > > Don’t look to techniques to determine if something is a success criteria. > > Look to the criteria itself to see if it is > > - testable > - applicable to all types of content it is scoped to apply to > - reasonable > - (requiring all web pages to be translated into sign language is > not currently reasonable or even possible - there arent enough people in > the world who know sign language to convert all the pages made in a day > into sign) (and if there is an automatic text to sign language ability - > there is no need to make alternate sign language pages because any page can > be converted on the fly) > > > > > Gregg > > > > > > > On Oct 28, 2015, at 11:15 AM, Detlev Fischer <detlev.fischer@testkreis.de> > wrote: > > Am 28.10.2015 um 16:17 schrieb Gregg Vanderheiden < > gregg@raisingthefloor.org>: > > And having testable techniques does not make up for a non-testable SC. > You need to be able to determine if the SC is met - not if a technique use > for some content on the page passes. > > > The thing is that there is no single test to determine if a SC is met, nor > a finite set of tests (because techniques are not required, and new > techniques to account for may emerge at any time - so in my view, this > implies that conformance to a SC can never be established In a > deterministic, fully replicable way (because this would require a fully > operationalized, completely documented test procedure that can be exactly > followed by anyone). > > I hope this does not come across as trolling. I think it is important to > set realistic expectations regarding the outcome of a11y testing of complex > content, and to realize that a conformance check is often not completely > objective. It includes common sense judgments that take on board both > quality (attributing "not ideal" content instances to either "pass" or > "fail", and assessing the a11y impact of issues found) and quantity (number > of issues on a particular page). > > Sent from phone > > And having testable techniques does not make up for a non-testable SC. > You need to be able to determine if the SC is met - not if a technique use > for some content on the page passes. > > >
Received on Thursday, 29 October 2015 09:17:44 UTC