By Will Pearson
[Editor’s Note: Although the blog has been mostly writing for entertainment value lately, I still work in the field and enjoy hearing various theories about user interface. Will is one of the most well studied in this field and one of its most insightful thinkers.]
I’ve recently found some time to continue with my work on simulating human visual attention using audition. This involves using multimodal user interface
techniques to simulate or provide the characteristics of a particular human behaviour, which in this case is visual attention. Working on simulating behaviour
has caused me to think about how the approach of providing accessibility by simulating behaviour differs from the current approach of treating accessibility
as a synonym for application compatibility.
The main problem with taking the approach of treating accessibility as a synonym for app compat is that it turns accessibility into an infinite set of problems
with no end in sight. Software developers are continuously producing new software products or modifying existing ones, and these have to be made to work
with assistive technology or vice versa. So, accessibility becomes a continual problem and the only beneficiaries of this are members of the accessibility
industry as they are guaranteed a continual revenue stream.
Providing accessibility by synthesising human behaviour has a significant advantage over the current approach of app compat. Humans have a limited set
of behaviours that need to be synthesised, and this means that accessibility can be viewed as a finite set of problems. Having a finite set means that
we can view accessibility as something that has an end point rather than something that is continuous. If we can find ways to synthesise all of the behaviours
that a particular disability affects then we would find ourselves in a situation where everything was automatically accessible to people with that particular
disability. Simply put, providing accessibility by synthesising behaviour makes complete accessibility an achievable goal rather than one we can never
achieve because to solve it requires that we solve a problem set of infinite size.
Unfortunately, when talking about computer based accessibility we do need to retain the idea of app compat in one instance. Assistive technology generally
acts as a translator that participates in the process of communication by translating between different types of sensory stimuli and or different lexicons
and sets of perceptual symbols. Communication involves passing messages between different parties. In the case of computer based assistive technology
the only party that the assistive technology really needs to communicate with is the operating system, and so the notion of app compat between assistive
technology and operating system will need to remain even if the view of accessibility changed so that accessibility was provided by synthesising behaviour;
however, if accessibility became a synonym for synthesising behaviour then we could eliminate app compat everywhere else.