[ossrp-control] Re: What Is A Screen Reader?

Hi Will and Others,

Will, I found your description of what a screen reader is quite interesting.  

I train people to use screen readers and, from my experience, some blind folk 
are interested in where things are on the screen (spacial perception) and 
others are not.  In particular, those who have had sight and were extremely 
visual people find it important to know where things are.  Some, and I say 
some, so therefore not all, long term blind people don't seem to be interested 
in the spacial factor.

I am a long term blind person and have always tried to grasp a mental picture 
of what is on the screen and where - probably because I teach both kinds of 
blind people and sometimes assist sighted folk.

Anyhow, I thought I'd share my experiences with you.

Cheers,
Lyn

----- Original Message ----- 
From: Will Pearson 
To: ossrp-control@xxxxxxxxxxxxx ; uvip@xxxxxxxxxxxxxxx 
Sent: Sunday, May 01, 2005 11:58 AM
Subject: [ossrp-control] What Is A Screen Reader?


Hi,

I thought I'd share my, rather academic, view of what a screen reader is.  It 
offers a little glimmer into what screen readers could potentially do, and some 
of the pitfalls that the current crop of screen readers have fallen into.  All 
this is from the viewpoint of human computer interaction, psychology and 
communications theory.

OK.  So, what is a screen reader?  Well, it's actually a lot more than people 
often assume it is.  It's not just something that grabs the text from the 
screen and reads it to you, well, at least it shouldn't be, it is in fact the 
interface by which user and machine communicate semantic meaning, relating to 
thoughts, concepts, actions and states.

So, how did I arrive at this view?  As some of you may know, I've been 
researching into semantics and their role in software interfaces for a while 
now.  During this time, it's become apparent that software interfaces are just 
intended to communicate semantic meaning, but as we're not capable of extr 
sensory perception and telepathy with the computer, we need some way to 
indicate our thoughts, concepts, actions, etc. to the computer, and vice versa. 
 The way this is visually done is by placing elements on the screen, such as 
icons, buttons, etc. and having their shape, colour, position on screen and 
relationships to one another act as encoding channels by which the semantic 
meaning is conveyed.  Users then just point to an object, conveying the 
semantics of which element they would like to interact with, and either click 
it or select an action to perform on it from a menu.  All this is just a form 
of physical encoding of the semantic meaning between user and machine and vice 
versa.

So, as a screen reader is a replacement for the visual interface, it's role is 
simply to act as an interface between user and machine and convey the semantic 
meaning generated by the machine.  However, there's a nasty twist, and that is 
that a screen reader has to get the semantic meaning that it is to communicate 
to the user from somewhere.  As the screen reader has no access to the 
internals of the machine, it's only available source of semantics that the 
machine wishes to convey is the visual interface, which uses encoding 
techniques such as colour, shape, position and spatial relationship to convey 
it's semantics.  So, a screen reader should really be about extracting the 
semantics from the visual display and encoding them in a non-visual form 
suitable for a blind user, and this is where current screen readers fall down.  
To maintain accurate and efficient communication with the user, all the 
semantics that are conveyed visually need to be conveyed to the user.  This 
includes things like spatial positioning and spatial relationships between 
interface elements, things that are currently lost to the user when they are 
using one of the current screen readers.  If this were to happen, then the 
number of errors, and according back-tracks and reissuing of commands that go 
along with errors, would decrease, and screen reader users would be more 
efficient beasts.

I haven't gone into design specifics, as they're for another day, and these can 
dramatically affect efficiency as well, but that's my thoughts of what a screen 
reader should be doing.  In focusing on the semantics, then it's likely that 
through the use of semantic translation access to all those difficult 
accessibility problems could be increased.

Will

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