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

MessageHi Jamal,

It's difficult to quantify the semantics conveyed by a particular physical 
encoding scheme in a general sort of way.  There's multiple characteristics of 
space, namely position, proximity and size.  These can convey semantics, or 
they may not, in one scenario, size may be used to convey relative importance, 
whilst in another scenario it may be used to differentiate between two or more 
groups of items by having the items in each group a different size compared to 
those in another group.  This is also true for other mechanisms by which 
semantics can be encoded visually, such as color, font, and font attributes 
such as bold, italic, etc.  So, it's very difficult to determine what 
semantics, if any, are encoded using a particular technique in a scenario 
devoid of context.

There's a couple of ways that this can be presented to a user.  Firstly, you 
can have some form of intelligent system that will extract the semantics from 
the visual presentation and convey the semantics to the user, either in raw 
form using additional spoken words, or by altering the attributes of the spoken 
text associated with the item for which the semantics are being conveyed.  The 
major drawback to this is that it's very hard to create the intelligence to do 
this in an autonomous manner, and so the system would have to be taught the 
relationships between encoding techniques and the semantics they convey in the 
various different contexts.

The second method of conveying the content is to take the encoded semantics, 
e.g. spatil position, color, etc. and convey this to the user but altering it's 
physical presentation.  So, instead of conveying spatial relationships through 
parallel presentation of different elements, you could convey the spatial 
positioning of each element, and thus the rrelationship, through a series of 
spoken co-ordinates, which would still leave space as the encoding technique 
for conveying semantics, but would modify the physical representation of that 
encoding to speech.  A similar thing could be done for color, where instead of 
altering te wavelength of the displayed element, you could just use speech to 
say the color of the item, which would still leave color conveying the 
semantics.  Alternatively, you could have parallel auditory displays that use 
different frequencies/wavelengths to present the information.

That's just some of the ways in which it could be done, and they're by no means 
designs.  One point that I think needs to be born in mind when thinking about 
this sort of thing is the limitations of speech.  Firstly it's serial in 
nature, and so the more you produce in terms of speech the more time it takes 
someone to receive that semantic content, and secondly, people have a short 
term memory limit of between five and nine chunks of information, at least 
according to George Miller's 'Magical number seven, plus or minus two' theory.  
Speech being serial in nature doesn't allow a user to very easily quickly jump 
back to a position to review the content at that position, so people tend to 
have to remember the content as they go, and this is stored in their limited 
short term memory.

I think it's something that needs some careful consideration to come up with 
the optimal design.

Will
  ----- Original Message ----- 
  From: Jamal Mazrui 
  To: ossrp-control@xxxxxxxxxxxxx 
  Sent: Thursday, May 05, 2005 9:22 PM
  Subject: [ossrp-control] Re: What Is A Screen Reader?


  Good point.  That is a different, more complex  example, but certainly such 
scenarios are also common.  I think the scenario that I described often occurs 
with order forms on the web, typically asking for contact and credit card 
information in a familiar pattern.

  In evaluating this issue, at least two questions seem relevant:  (1) what 
does spatial information convey about the function of the dialog? and (2) to 
the extent that functional rather than asthetic information is being conveyed, 
what is the best way to achieve an equivalent result nonvisually?  

  If there are optional subgroups of fields, then tabbing through all of them 
is, indeed, inefficient.  To achieve productive data entry, let us separate 
function from presentation.  The blind person probably does not need to know, 
for example, how many pixels separate controls in order to judge which ones are 
part of the same subgroup and which are part of another.  The fact that the 
border of group boxes uses a 3D rather than simple style is inconsequential.  
The objective is to enable the blind person to identify and navigate to the 
different subgroups.  For the screen reader user, a multi-page tab dialog might 
be the most efficient solution rather than a single page dialog where subgroups 
are indicated by spatial proximity.

  Jamal


  -----Original Message-----
  From: ossrp-control-bounce@xxxxxxxxxxxxx 
[mailto:ossrp-control-bounce@xxxxxxxxxxxxx] On Behalf Of David Lant
  Sent: Thursday, May 05, 2005 3:46 PM
  To: ossrp-control@xxxxxxxxxxxxx
  Subject: [ossrp-control] Re: What Is A Screen Reader?


  Hi Jamal,

  Broadly I understand your point.  However, there are situations where simply 
going sequentially through the items in a dialog is not the process required 
for daily use of a facility.  If, for example, your job is processing pay 
claims, and allocating charge codes to the relevant portions of hourly rates, 
overtime rates, expenses and so on, it would, and does, become extremely 
tedious having to tab through all the fields that may have to be displayed to 
inform you what needs to be done.

  It may be much quicker, if the pieces of information are all grouped in one 
control group, and the fields you need to fill in are in an adjacent one.  
There may very likely be other data on the screen at the same time, which don't 
relate directly to the job in hand.  Sighted people visually skip over that 
stuff, such as the box at the top giving the identification summary of the 
person and their pay reference etc.  They see that the boxes they need to work 
with are all in two rectangles on the right of the screen, one above the other, 
and so visually concentrate on those.  They will glance through the information 
in the first box, to identify the hours being claimed, and will then click in 
the second box to place an insertion pointer so they can type in the relevant 
charge codes.

  For a blind person to do this, they would need to have a quick way to rapidly 
get to the information in the upper right box, and read it.  Then, to equally 
rapidly, move to the lower right box, in order to start filling in the 
information.  It is true that the fact that these boxes are on the right of the 
screen may be of no significance whatsoever as far as both the blind and 
sighted person are concerned.  But the significance is that they separate out 
the information that has to be dealt with, so that the details on the left of 
the screen can be largely ignored unless something special turns up.

  This, I think, is the kind of scenario that Will is talking about.  Not just 
the fact that address fields are grouped together, but that you may need to 
perform specific, and isolated tasks on that group, separate from the rest of 
the data on the screen.

  All the best, 
  David 

    -----Original Message-----
    From: ossrp-control-bounce@xxxxxxxxxxxxx 
[mailto:ossrp-control-bounce@xxxxxxxxxxxxx] On Behalf Of Jamal Mazrui
    Sent: 05 May 2005 08:21
    To: ossrp-control@xxxxxxxxxxxxx
    Subject: [ossrp-control] Re: What Is A Screen Reader?


    Hi Will,
    I agree that spatial relationships can and do convey a lot of information 
to sighted users.  I was not arguing that visual placement is generally 
irrelevant, but maintain that it can be so for blind users where it does not 
affect the interface we experience and the functionality of the task at hand.  

    For example, if the purpose of a dialog is to retrieve typical contact 
information (name, address, phone, etc.) through a well-understood set of 
fields, then it may be irrelevant to the blind user where the controls are 
placed, as long as they speak properly.  The layout of the dialog is not an end 
in itself, but a means to an end, that of gathering the data for a contact 
record.  The database does not care, and does not track, where the controls 
were placed in the input dialog that gathered the data for the record that was 
saved.

    To elaborate, I might press tab successively hearing fields like "First 
name", "last name," etc., filling each one in, including reviewing the data in 
each edit box.  If the tab order is logical and the field name and current 
value speak as expected, than it does not matter to me how the fields are 
aligned, what fonts are used for field names, what point size the entered 
characters are, etc.

    Sighted users, on the other hand, are affected by such characteristics.  
Even if the tab order is the same, logical sequence, they will be confused if 
the "City" field is placed above the "First Name" field.  If a few fields are 
cramped together in one corner of the dialog in an unpleasing manner 
aesthetically, their productivity will be reduced because of the disorientation 
they experience, etc.

    Jamal

     -----Original Message-----
    From: ossrp-control-bounce@xxxxxxxxxxxxx 
[mailto:ossrp-control-bounce@xxxxxxxxxxxxx] On Behalf Of Will Pearson
    Sent: Wednesday, May 04, 2005 4:25 PM
    To: ossrp-control@xxxxxxxxxxxxx
    Subject: [ossrp-control] Re: What Is A Screen Reader?


    Hi Jamal,

    "As a blind user, placement
    can actually be irrelevant, having  no effect on functionality."

    Based on psychology, semiotics and communications theory, I would have to 
disagree with that statement.  A control's relationship to other controls and 
it's absolute positioning can be sources of semantic information about that 
control's functionality.  For example. buttons grouped together may have 
similar functionality, buttons placed next to a list box may perform an action 
on that list box or it's selected index.  On the web, a row of links placed in 
vertical alignment at the top of a page are often used as a quick navigational 
group of links.

    So. spatial relationships and absolute positioning can add a lot of meaning 
regarding functionality beyond that conveyed by a simple text label.  Users 
can, and often do, work out the full semantic nature of a control, but this is 
often through trying out the control and seeing what it does, which is 
inefficient at best, and possibly disasterous at worst, imagine deleting 
something that you didn't actually mean to delete.

    Will
      ----- Original Message ----- 
      From: Jamal Mazrui 
      To: ossrp-control@xxxxxxxxxxxxx 
      Sent: Monday, May 02, 2005 2:41 PM
      Subject: [ossrp-control] Re: What Is A Screen Reader?


      Just an observation to share.

      In trying to program dialog boxes under Windows, I have experienced the 
situation where something I developed worked well with a screen reader, yet I 
subsequently discovered that it was almost unusable for a sighted person.  A 
screen reader can tab from one control to another, and as long as each control 
is properly labeled and otherwise voicing as one would expect at the time it 
has focus, then the controls in the dialog serve their purpose.  It may be the 
case, however, that the controls are placed in visually peculiar, unbalanced, 
or overlapping places on the screen, thus making the dialog difficult for a 
sighted user.

      As a blind developer, I need to know the location of controls so that I 
can meet the needs of both sighted and blind users.  As a blind user, placement 
can actually be irrelevant, having  no effect on functionality.

      Regards,
      Jamal
      -----Original Message-----
      From: ossrp-control-bounce@xxxxxxxxxxxxx 
[mailto:ossrp-control-bounce@xxxxxxxxxxxxx] On Behalf Of Lyn Eagers
      Sent: Saturday, April 30, 2005 11:19 PM
      To: ossrp-control@xxxxxxxxxxxxx
      Subject: [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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