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Re: Auto-WCAG - Expert system approach?

From: Alistair Garrison <alistair.garrison@ssbbartgroup.com>
Date: Wed, 26 Oct 2016 08:16:38 +0000
To: John Hicks <jwjhix@gmail.com>, "public-auto-wcag@w3.org" <public-auto-wcag@w3.org>
Message-ID: <D6EE7277-FEEA-4B1B-A46A-7AF2D21A19F4@ssbbartgroup.com>
Hi John, All,

The fundamental shift over to expert-system type “rules” also came with the development of https://www.w3.org/community/auto-wcag/wiki/Template:UserInput.  This shift would not, almost certainly, have been made based on a mentioned reference to a tool by a participant.  Certainly, for a shift to take place group consensus must have been sort – about moving to expert-system type rules, over the more atomic rules people had been previously working on (for example, in the EIII project’s http://checkers.eiii.eu/).

Mikael mentioned the “EIII project’s User Testing Tool”, which could well have been the expert-system being referenced - but this is very much in its infancy, and seemingly no longer in development.

So then, if no one in the group is currently developing an expert-system (is anyone?); and we have several in the group developing tools that run more atomic tests (like the EIII tests) - my question to the group is still “are we developing Auto-WCAG rules for an expert system tool”? and, if yes – why exactly?

Especially when all my personal experience to date, and seemingly John’s personal experience (with regard to the first bullet), indicates that such expert-system interview-based tools:

-          become so very tedious so quickly to use;

-          take ages to develop (as “rules” are so inter-dependent);

-          will almost certainly not fit the broad-scale auto-monitoring usecase, as they require user interaction at many interim stages in tests; and

-          are only as accurate as the user’s judgement – which was surely what we’re trying to avoid by having a base set of agreed fully automatic tests we could compare results from.

Again, very interested to hear from Wilco / group members.

All the best


Alistair Garrison
Senior Accessibility Engineer
SSB Bart Group

From: John Hicks <jwjhix@gmail.com>
Date: Tuesday, 25 October 2016 at 13:24
To: Alistair Garrison <alistair.garrison@ssbbartgroup.com>
Cc: "public-auto-wcag@w3.org" <public-auto-wcag@w3.org>
Subject: Re: Auto-WCAG - Expert system approach?

Dear Alistair,
I am not sure exactly which meeting it was or if it referred to something I might have said :
Urbilog.fr has developped 3 automatic testing tools based on Expert System in the AI sense.

The "Expert" part was not user input but the "clips" expert system as created by nasa :  https://en.wikipedia.org/wiki/CLIPS

The essence of the idea is to transform each HTML element into a statement in a declarative language and then test the truth of these statements w.r.t. the rule-set in question (508 and Wcag 1 in the beginning, RGAA later).
One of these tools also had the question and answer part, which, as you say becomes so very tedious so quickly.
I am still hoping to get one of these applications, designed for IBM initially, but to which the IP rights belong to the developper, into open source.

On 25 October 2016 at 14:07, Alistair Garrison <alistair.garrison@ssbbartgroup.com<mailto:alistair.garrison@ssbbartgroup.com>> wrote:
Hi Wilco, All,

In the July 2015 Auto-WCAG blog - https://www.w3.org/community/auto-wcag/2015/07/24/introducing-the-auto-wcag-user-input-template/, under Next steps I was reading that:

“Some participants of the auto-wcag community group are currently implementing the prototype of a User Testing Tool based on the questions developed in the structured approach described in this post. The tool runs in the user’s web browser and connects to a database storing the user input.”

Out of interest, could I ask which participants are working on this “expert-system” tool? And, if work is still under way?
I too developed an interview based expert-system ages ago – for testing the accessibility of a web page (thankfully they were more static back then).

With all such systems you call your tests “rules”, and you follow a very similar grammar to the one proposed in Auto-WCAG.  I used Jess formatting initially (http://herzberg.ca.sandia.gov/), then developed my own system…
I finalised my expert system some years ago – it looked at WCAG 1.0 AA.  I demoed it to several organisations, and got some good reviews!
The issue was that although an interesting way to proceed – only when you actually used it for commercial audits did you realize how slow such as process is.  The same questions have to be asked again and again of the user – for example, for each img node – which is overkill if you are only looking to find enough faults to show something is an issue.

For example, http://wilcofiers.github.io/auto-wcag/rules/SC1-1-1-text-alternative.html - Contains questions you need to ask the user about each image – “Is this element solely for decorative purposes”?

With actual implementation knowledge, it is certainly not an approach I would suggest for large-scale monitoring purposes, as it simply takes too long to assess each page looked at; and requires human judgement which can be wildly different.   Auto-WCAG tests, being formatted in a very specific way, also will not slip easily into other testing platforms.
My understanding was that we were concentrating on developing fully automatic tests – which could be plugged into any testing platform – the output from which could easily be compared.

With manual steps in a number of the current tests, which also include design constraints such as “Presented item - Web page (with title either highlighted or in a seperate textbox)”, I think we are making it hard for ourselves to achieve the comparability goal; or even create tests that achieve AUTO-WCAG’s desired aims.

It would only take a short amount of time to re-assemble the current “rules” into sets of atomic fully-automated tests – by leaving the manual testing steps aside; and I wonder if this isn’t the direction we should be moving in instead – and may prove significantly quicker.  Which, I also should mention seems to have been the approach of the EIII project from which Auto-WCAG was initially born (http://checkers.eiii.eu/en/tests/).

My question to the group is “are we developing Auto-WCAG rules for an expert system tool”? and, if yes – why exactly?

I’d be very interested to discuss the above, and hear comments from the whole group.
All the best
Alistair Garrison
Senior Accessibility Engineer
SSB Bart Group

Received on Wednesday, 26 October 2016 08:17:15 UTC

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