Re: accessible name computation & changing button labels

Hi Adam,
In our work on interactive science simulations, we come across this issue often.

We have found through evaluation with blind learners that in many cases it is important to overtly communicate the change, and not leave the change solely to the changed label on the button. Overtly communicating the change creates a sense of assurance that the learner’s action was successful. I don’t see this as a hack, but rather good design.

In our case, we do indeed use live regions to announce the success of the change. Sometimes, however, the interaction itself is clear enough and the change is simple enough that an announcement is not needed. For example, I have found that some radio button interactions do not need an overt announcement of the change that is made. For certain changes the “selected, not selected” information together with well-chosen accessible names for the radio buttons is enough to communicate the interaction effectively.

Our situation may be somewhat unique, we do not build web forms, but rather highly interactive learning tools. Employing live regions is essential for communicating all sorts of changes. 

For an example of a simple button with a visible label change that also includes an announcement of that change, please see the “Remove Wall” button in the Balloons and Static Electricity <https://phet.colorado.edu/en/simulation/balloons-and-static-electricity> simulation. In this simulation, I also found it important to delivery “responses” or announcements for each of the radio buttons that changes the way charges are shown. 

However, in another sim, Molecules and Light <https://phet.colorado.edu/en/simulation/molecules-and-light>  learners told me that when they chose a new the light source or a new molecule, that is was clear that they were setting up a new situation in the Observation Window. In this case, due to the surrounding information, there was no need to overtly announce that the light source or molecule in the Observation Window was changed. Molecules and Light uses the switch role on the Light Source button which also has a dynamic label depending on which light source is currently selected. When the the switch is turned on or off, we announce it, again this is done with aria live regions.

To hear the words, you need to be using a screen reader. For our simulations, we test with these three different screen reader/ browser combinations: Voice Over with Safari, NVDA with Firefox, and JAWS with Chrome. The simulations do work in other configurations, but we do not test other configurations.

I hope you enjoy the examples, and that they are helpful. I can’t say that your situation needs an overt announcement. I can say, though, that if the change is not clear from the interaction itself, users may indeed appreciate an announcement.

Taliesin Smith
talilief@gmail.com

~.~.~
Also reachable at off-list:
Taliesin.Smith@colorado.edu
Inclusive Design Researcher
PhET Interactive Simulations
https://phet.colorado.edu/en/accessibility
Physics Department
University of Colorado, Boulder




> On Oct 14, 2020, at 4:29 AM, Adam Cooper <cooperad@bigpond.com> wrote:
> 
> Hi all … working on a project at the moment with buttons whose label changes when pressed .. can’t get a screen reader to announce the changed label in situ (i.e., when focus remains on the button).  
>  
> Adding aria-live to the button or somewhere else on the screen just seems like an ugly hack from yesteryear and it causes unnecessary repetition.
>  
> Just wondering, first, what the accessible name computation algorithm says about this case or what the spec behaviour should  be, and, second, whether anyone has any tips on how to resolve this?
>  
> Cheers,
> Adam