[accessibleimage] Re: An antidote to CSUN
- From: "Darrell Shandrow" <nu7i@xxxxxxxxxxxxx>
- To: <accessibleimage@xxxxxxxxxxxxx>
- Date: Mon, 17 Apr 2006 10:31:01 -0700
Hi John and all,
I also feel that insisting on accessibility to existing assistive technology
is all we've got as blind people now and for the foreseeable future. It is
hard enough to get mainstream industry to cooperate with us to provide
adequate accessibility as it stands, and the blind community, by and large,
lacks the willpower necessary to absolutely insist on that crucial access.
It is thus potentially dangerous for us to go throwing the baby out with the
bathwater, so to speak. Sorry if I seem very gloomy about all this, but I
almost lost my job a couple of months ago due to an inaccessible Siebel
implementation...
Darrell Shandrow - Shandrow Communications!
Technology consultant/instructor, network/systems administrator!
A+, CSSA, Network+!
Visit http://www.petitiononline.com/captcha and sign the Google Word
Verification Accessibility Petition today!
Information should be accessible to us without need of translation by
another person.
Blind Access Journal blog and podcast: http://www.blindaccessjournal.com
----- Original Message -----
From: "John Panarese" <tvii@xxxxxxxxxxxxx>
To: <accessibleimage@xxxxxxxxxxxxx>
Sent: Monday, April 17, 2006 10:03 AM
Subject: [accessibleimage] Re: An antidote to CSUN
Hi
You are not the first person I've heard make this claim, and I've
heard sighted people offer similar assertions. For example as much as a
screen reader user may be lacking in the six factors, in general, the
average blind computer user tends to know far more than the average
sighted
computer user. This is simply because one who is blind and utilizes a
screen
reader has to become much more familiar and versed in some of the
intricacies the average sighted user never has to deal with at all. Thus,
this same principle can be extended to other work related tasks.
Take Care
John D. Panarese
Managing Director
Technologies for the Visually Impaired, Inc.
9 Nolan Court
Hauppauge, NY 11788
Tel/Fax, (631) 724-4479
Email, tvii@xxxxxxxxxxxxx
Internet, http://www.tvi-web.com
AUTHORIZED DISTRIBUTORS FOR PORTSET SYSTEMS LTD, COMPSOLUTIONS VA, PREMIER
ASSISTIVE TECHNOLOGIES, INDEX, PAPENMEIER, REPRO-TRONICS, PULSEDATA,
DUXBURY, DANCING DOTS, ROBOTRON AND OTHER PRODUCTS FOR THE BLIND AND
VISUALLY IMPAIRED
-----Original Message-----
From: accessibleimage-bounce@xxxxxxxxxxxxx
[mailto:accessibleimage-bounce@xxxxxxxxxxxxx] On Behalf Of Darrell
Shandrow
Sent: Monday, April 17, 2006 12:33 PM
To: accessibleimage@xxxxxxxxxxxxx
Subject: [accessibleimage] Re: An antidote to CSUN
Hi Lisa,
Alas, I'm afraid Will's article is much gloomier than all that as both
full
page Braille and tactile graphics are still methods of serial information
retrieval and processing.
Now, I am about to say something that some may find offensive but I just
can't hold out any longer. Despite our apparent shortcomings as blind
people (being unable to do parallel info retrieval without sight, etc.)
I'd
put a competent blind worker up against a sighted one anyday. Why? Alas,
as I live my life out in the real world, I find that most sighted people,
for whatever reasons, choose not to use the brains and other abilities
given
them by God. So, in other words, while most people (whom happen to be
sighted) apparently have all these abilities I lack as a blind person, I
find I am often able to best them through competent performance of the
task
at hand...
Darrell Shandrow - Shandrow Communications!
Technology consultant/instructor, network/systems administrator!
A+, CSSA, Network+!
Visit http://www.petitiononline.com/captcha and sign the Google Word
Verification Accessibility Petition today!
Information should be accessible to us without need of translation by
another person.
Blind Access Journal blog and podcast: http://www.blindaccessjournal.com
----- Original Message -----
From: "Lisa Yayla" <fnugg@xxxxxxxxx>
To: <accessibleimage@xxxxxxxxxxxxx>
Sent: Monday, April 17, 2006 9:13 AM
Subject: [accessibleimage] Re: An antidote to CSUN
Hi Will,
It was very interesting to read your letter. I really enjoyed it. And
if I understand correctly it seems also to strengthen the argument
that tactile graphics are important. That it is important to have
non-linear information and for the blind this is done through tactile
graphics - staggered information. Or how would you call tactile graphics?
Non-serialized information?
And does this also say something about the importance of reading
Braille in page form?
Regards,
Lisa
why learning Braille is important
accessibleimage@xxxxxxxxxxxxx wrote:
Hi,
Now that all the hype of CSUN is behind us, I thought it time to
begin to explore the more serious questions, the sort that are rarely
touched on at CSUN. The first question I felt worthy of an attempt
at an answer is, whether using a screen reader can ever be as
efficient as using sight?
There's been plenty of speculation on the topic, usually resulting in
the answer that if <insert application vendor or platform vendor>
waived their magic wand using a screen reader would be as efficient
as sight.
However,
after spending several years considering this, and other human
computer interaction issues related to screen reader use, I take a
different view.
My justification, whilst not exhaustive, is below.
The first area where screen readers appear to fall short is in their
ability to communicate semantics. Communication is all about
communicating thoughts, concepts, states, etc., and communication
between an interface for a piece of software and a user is no
different in this respect. The main problem is that screen readers,
through their use of speech and Braille, both of which are serialised
forms of communication, use less physical variables to encode semantic
content than sight does.
There's roughly six variables that can be used to encode semantic
content, and these are:
* The position of something on the X, Y and Z axes
* The position of something in time
* The frequency of the physical wave, represented by things like
color, pitch, etc.
* The amplitude of the physical wave, or how strong it is Using a
computer with sight typically takes advantage of five of these
variables, whilst screen readers typically only use two. So, it will
take longer to communicate the same semantic content using a screen
reader than it will sight. To some extent this has supporting
evidence from psychological studies in which the listening and
reading speeds of the same person were compared. These studies found
that the same individual could read something faster than they could
listen to it. There are differences between individuals, which can
account for why some screen reader users can listen to things faster
than some people can read things, but within the same individual the
evidence seems to indicate that listening to things is slower.
This serialisation of semantic content, brought about by the smaller
capacity of speech, also has implications for memory utilisation and
cognitive workload. Studies involving Functional Magnetic Resonance
Imaging of the cortex have shown greater activity in the cortical
regions of the brain when listening to speech than when reading
something. Not only is there activity on the left side of the
cortex, in regions such as Brocha's Area and Wernicke's Area, which
is present for both reading and listening, but listening to speech
also produces activity in the right side of the cortex, which is thought
to be related to contextual priming.
In addition to the extra neurological activity associated with
language processing, there is also a higher demand on short term working
memory.
As speech is temporary, one moment it is there, the next it is not,
someone listening to speech has to remember more than someone reading
something. It is not so easy to move back to a previously listened
to word or sentence than it is to move back to a previously read word
or sentence. Navigating by listening often involves listening to
words, deciding whether they are the ones that are saught after, and
if not, navigating some more and repeating the process.
Another consideration are the distinctions between programatic
focus, the mechanism used to shift attention with a screen reader,
and visual attention. Screen readers utilise a mechanism of
programatic focus to shift the user's attention between user
interface elements. This means that a user's attention is only
focused on a single point at once, something further compounded by a
screen reader's use of serialised output. Whilst visual attention is
usually focused on a single object, it can shrink and grow, similar
to a zoom lens, to encompass more or less of an object. This ability
to shift attention from a word to a paragraph and then onto the
entire document provides a number of benefits for people reading
documents. The most obvious benefit is the ability to not only
navigate by word or line, but to navigate around the document based
on more granular objects, such as paragraphs, tables, images, etc.
Whilst similar functionality is available in some screen readers for
a limited set of scenarios, this functionality is not as flexible as
the visual mechanism used to shift attention. The visual mechanism
can group granular objects together, such as a table proceeded by a
diagram, and can jump to those with very little requirement for
processing. In addition to granular navigation, attention can also
be shifted based on physical features, such as color or location,
which requires just the elements with those physical features to be
searched, as suggested by Treisman's Feature Integration Theory. As
far as I am aware, no equivalent functionality to this exists in a
screen reader. One key difference between programatic and visual
attention is that programatic attention can only be moved to fixed
points, whilst visual attention can be moved to any point or object.
The final difference worth mentioning is that attention is not just
limited to a single point in the visual field. Whilst there are
overt, indogenous, mechanisms to control visual attention through
moving the point of fixation, attention can also be focused in the
periphery of the visual field, through covert, indogenous,
mechanisms. This is a useful point, as it means that sighted people
can detect changes in the state of something that occur away from
their current point of fixation without the cognitive work involved
in moving the point of fixation So, I, for one, am beginning to form
the opinion that screen readers are not physically capable of
delivering the same levels of efficiency as sight can. This isn't to
say that blind people cannot gain the same level of efficiency, just
that it looks likely that they are unable to do this using a screen
reader. What is more, is that this is not the fault of a particular
application or platform vendor, as is often claimed, but more a
problem with the core concept of a screen reader, a concept that
requires everything to be serialised.
Will
---------------------------------------------------------------------
---
Hi,
Now that all the hype of CSUN is behind us, I thought it time to
begin to explore the more serious questions, the sort that are rarely
touched on at CSUN. The first question I felt worthy of an attempt
at an answer is, whether using a screen reader can ever be as
efficient as using sight? There's been plenty of speculation on the
topic, usually resulting in the answer that if <insert application
vendor or platform
vendor> waived their magic wand using a screen reader would be as
efficient as sight. However, after spending several years
considering this, and other human computer interaction issues related
to screen reader use, I take a different view. My justification,
whilst not exhaustive, is below.
The first area where screen readers appear to fall short is in their
ability to communicate semantics. Communication is all about
communicating thoughts, concepts, states, etc., and communication
between an interface for a piece of software and a user is no
different in this respect. The main problem is that screen readers,
through their use of speech and Braille, both of which are serialised
forms of communication, use less physical variables to encode semantic
content than sight does.
There's roughly six variables that can be used to encode semantic
content, and these are:
* The position of something on the X, Y and Z axes
* The position of something in time
* The frequency of the physical wave, represented by things like
color, pitch, etc.
* The amplitude of the physical wave, or how strong it is Using a
computer with sight typically takes advantage of five of these
variables, whilst screen readers typically only use two. So, it will
take longer to communicate the same semantic content using a screen
reader than it will sight. To some extent this has supporting
evidence from psychological studies in which the listening and
reading speeds of the same person were compared. These studies found
that the same individual could read something faster than they could
listen to it.
There are differences between individuals, which can account for why
some screen reader users can listen to things faster than some people
can read things, but within the same individual the evidence seems to
indicate that listening to things is slower.
This serialisation of semantic content, brought about by the smaller
capacity of speech, also has implications for memory utilisation and
cognitive workload. Studies involving Functional Magnetic Resonance
Imaging of the cortex have shown greater activity in the cortical
regions of the brain when listening to speech than when reading
something. Not only is there activity on the left side of the
cortex, in regions such as Brocha's Area and Wernicke's Area, which
is present for both reading and listening, but listening to speech
also produces activity in the right side of the cortex, which is thought
to be related to contextual priming.
In addition to the extra neurological activity associated with
language processing, there is also a higher demand on short term working
memory.
As speech is temporary, one moment it is there, the next it is not,
someone listening to speech has to remember more than someone reading
something. It is not so easy to move back to a previously listened
to word or sentence than it is to move back to a previously read word
or sentence. Navigating by listening often involves listening to
words, deciding whether they are the ones that are saught after, and
if not, navigating some more and repeating the process.
Another consideration are the distinctions between programatic
focus, the mechanism used to shift attention with a screen reader,
and visual attention. Screen readers utilise a mechanism of
programatic focus to shift the user's attention between user
interface elements. This means that a user's attention is only
focused on a single point at once, something further compounded by a
screen reader's use of serialised output. Whilst visual attention is
usually focused on a single object, it can shrink and grow, similar
to a zoom lens, to encompass more or less of an object. This ability
to shift attention from a word to a paragraph and then onto the
entire document provides a number of benefits for people reading
documents. The most obvious benefit is the ability to not only
navigate by word or line, but to navigate around the document based on
more granular objects, such as paragraphs, tables, images, etc.
Whilst similar functionality is available in some screen readers for
a limited set of scenarios, this functionality is not as flexible as
the visual mechanism used to shift attention. The visual mechanism
can group granular objects together, such as a table proceeded by a
diagram, and can jump to those with very little requirement for
processing. In addition to granular navigation, attention can also
be shifted based on physical features, such as color or location,
which requires just the elements with those physical features to be
searched, as suggested by Treisman's Feature Integration Theory. As
far as I am aware, no equivalent functionality to this exists in a
screen reader. One key difference between programatic and visual
attention is that programatic attention can only be moved to fixed
points, whilst visual attention can be moved to any point or object.
The final difference worth mentioning is that attention is not just
limited to a single point in the visual field. Whilst there are
overt, indogenous, mechanisms to control visual attention through
moving the point of fixation, attention can also be focused in the
periphery of the visual field, through covert, indogenous,
mechanisms. This is a useful point, as it means that sighted people
can detect changes in the state of something that occur away from
their current point of fixation without the cognitive work involved
in moving the point of fixation So, I, for one, am beginning to form
the opinion that screen readers are not physically capable of
delivering the same levels of efficiency as sight can. This isn't to
say that blind people cannot gain the same level of efficiency, just
that it looks likely that they are unable to do this using a screen
reader. What is more, is that this is not the fault of a particular
application or platform vendor, as is often claimed, but more a
problem with the core concept of a screen reader, a concept that
requires
everything to be serialised.
Will
- Follow-Ups:
- [accessibleimage] Re: An antidote to CSUN
- From: John Panarese
- References:
- [accessibleimage] Re: An antidote to CSUN
- From: John Panarese
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- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
- » [accessibleimage] Re: An antidote to CSUN
You are not the first person I've heard make this claim, and I've
heard sighted people offer similar assertions. For example as much as a
screen reader user may be lacking in the six factors, in general, the
average blind computer user tends to know far more than the average sighted
computer user. This is simply because one who is blind and utilizes a screen
reader has to become much more familiar and versed in some of the
intricacies the average sighted user never has to deal with at all. Thus,
this same principle can be extended to other work related tasks.
Take Care
John D. Panarese Managing Director Technologies for the Visually Impaired, Inc. 9 Nolan Court Hauppauge, NY 11788 Tel/Fax, (631) 724-4479 Email, tvii@xxxxxxxxxxxxx Internet, http://www.tvi-web.com
AUTHORIZED DISTRIBUTORS FOR PORTSET SYSTEMS LTD, COMPSOLUTIONS VA, PREMIER ASSISTIVE TECHNOLOGIES, INDEX, PAPENMEIER, REPRO-TRONICS, PULSEDATA, DUXBURY, DANCING DOTS, ROBOTRON AND OTHER PRODUCTS FOR THE BLIND AND VISUALLY IMPAIRED
-----Original Message-----
From: accessibleimage-bounce@xxxxxxxxxxxxx
[mailto:accessibleimage-bounce@xxxxxxxxxxxxx] On Behalf Of Darrell Shandrow
Sent: Monday, April 17, 2006 12:33 PM
To: accessibleimage@xxxxxxxxxxxxx
Subject: [accessibleimage] Re: An antidote to CSUN
Hi Lisa,
Alas, I'm afraid Will's article is much gloomier than all that as both full
page Braille and tactile graphics are still methods of serial information
retrieval and processing.
Now, I am about to say something that some may find offensive but I just
can't hold out any longer. Despite our apparent shortcomings as blind
people (being unable to do parallel info retrieval without sight, etc.) I'd
put a competent blind worker up against a sighted one anyday. Why? Alas,
as I live my life out in the real world, I find that most sighted people,
for whatever reasons, choose not to use the brains and other abilities given
them by God. So, in other words, while most people (whom happen to be
sighted) apparently have all these abilities I lack as a blind person, I
find I am often able to best them through competent performance of the task
at hand...
Darrell Shandrow - Shandrow Communications! Technology consultant/instructor, network/systems administrator! A+, CSSA, Network+! Visit http://www.petitiononline.com/captcha and sign the Google Word Verification Accessibility Petition today! Information should be accessible to us without need of translation by another person. Blind Access Journal blog and podcast: http://www.blindaccessjournal.com ----- Original Message ----- From: "Lisa Yayla" <fnugg@xxxxxxxxx> To: <accessibleimage@xxxxxxxxxxxxx> Sent: Monday, April 17, 2006 9:13 AM Subject: [accessibleimage] Re: An antidote to CSUN
different view.Hi Will,
It was very interesting to read your letter. I really enjoyed it. And if I understand correctly it seems also to strengthen the argument that tactile graphics are important. That it is important to have non-linear information and for the blind this is done through tactile graphics - staggered information. Or how would you call tactile graphics? Non-serialized information?
And does this also say something about the importance of reading Braille in page form?
Regards, Lisa
why learning Braille is important
accessibleimage@xxxxxxxxxxxxx wrote:Hi, Now that all the hype of CSUN is behind us, I thought it time to begin to explore the more serious questions, the sort that are rarely touched on at CSUN. The first question I felt worthy of an attempt at an answer is, whether using a screen reader can ever be as efficient as using sight? There's been plenty of speculation on the topic, usually resulting in the answer that if <insert application vendor or platform vendor> waived their magic wand using a screen reader would be as efficient as sight. However, after spending several years considering this, and other human computer interaction issues related to screen reader use, I take a
content than sight does.My justification, whilst not exhaustive, is below. The first area where screen readers appear to fall short is in their ability to communicate semantics. Communication is all about communicating thoughts, concepts, states, etc., and communication between an interface for a piece of software and a user is no different in this respect. The main problem is that screen readers, through their use of speech and Braille, both of which are serialised forms of communication, use less physical variables to encode semantic
to be related to contextual priming.There's roughly six variables that can be used to encode semantic content, and these are: * The position of something on the X, Y and Z axes * The position of something in time * The frequency of the physical wave, represented by things like color, pitch, etc. * The amplitude of the physical wave, or how strong it is Using a computer with sight typically takes advantage of five of these variables, whilst screen readers typically only use two. So, it will take longer to communicate the same semantic content using a screen reader than it will sight. To some extent this has supporting evidence from psychological studies in which the listening and reading speeds of the same person were compared. These studies found that the same individual could read something faster than they could listen to it. There are differences between individuals, which can account for why some screen reader users can listen to things faster than some people can read things, but within the same individual the evidence seems to indicate that listening to things is slower. This serialisation of semantic content, brought about by the smaller capacity of speech, also has implications for memory utilisation and cognitive workload. Studies involving Functional Magnetic Resonance Imaging of the cortex have shown greater activity in the cortical regions of the brain when listening to speech than when reading something. Not only is there activity on the left side of the cortex, in regions such as Brocha's Area and Wernicke's Area, which is present for both reading and listening, but listening to speech also produces activity in the right side of the cortex, which is thought
memory.In addition to the extra neurological activity associated with language processing, there is also a higher demand on short term working
content than sight does.As speech is temporary, one moment it is there, the next it is not, someone listening to speech has to remember more than someone reading something. It is not so easy to move back to a previously listened to word or sentence than it is to move back to a previously read word or sentence. Navigating by listening often involves listening to words, deciding whether they are the ones that are saught after, and if not, navigating some more and repeating the process. Another consideration are the distinctions between programatic focus, the mechanism used to shift attention with a screen reader, and visual attention. Screen readers utilise a mechanism of programatic focus to shift the user's attention between user interface elements. This means that a user's attention is only focused on a single point at once, something further compounded by a screen reader's use of serialised output. Whilst visual attention is usually focused on a single object, it can shrink and grow, similar to a zoom lens, to encompass more or less of an object. This ability to shift attention from a word to a paragraph and then onto the entire document provides a number of benefits for people reading documents. The most obvious benefit is the ability to not only navigate by word or line, but to navigate around the document based on more granular objects, such as paragraphs, tables, images, etc. Whilst similar functionality is available in some screen readers for a limited set of scenarios, this functionality is not as flexible as the visual mechanism used to shift attention. The visual mechanism can group granular objects together, such as a table proceeded by a diagram, and can jump to those with very little requirement for processing. In addition to granular navigation, attention can also be shifted based on physical features, such as color or location, which requires just the elements with those physical features to be searched, as suggested by Treisman's Feature Integration Theory. As far as I am aware, no equivalent functionality to this exists in a screen reader. One key difference between programatic and visual attention is that programatic attention can only be moved to fixed points, whilst visual attention can be moved to any point or object. The final difference worth mentioning is that attention is not just limited to a single point in the visual field. Whilst there are overt, indogenous, mechanisms to control visual attention through moving the point of fixation, attention can also be focused in the periphery of the visual field, through covert, indogenous, mechanisms. This is a useful point, as it means that sighted people can detect changes in the state of something that occur away from their current point of fixation without the cognitive work involved in moving the point of fixation So, I, for one, am beginning to form the opinion that screen readers are not physically capable of delivering the same levels of efficiency as sight can. This isn't to say that blind people cannot gain the same level of efficiency, just that it looks likely that they are unable to do this using a screen reader. What is more, is that this is not the fault of a particular application or platform vendor, as is often claimed, but more a problem with the core concept of a screen reader, a concept that requires everything to be serialised. Will
--------------------------------------------------------------------- ---
Hi, Now that all the hype of CSUN is behind us, I thought it time to begin to explore the more serious questions, the sort that are rarely touched on at CSUN. The first question I felt worthy of an attempt at an answer is, whether using a screen reader can ever be as efficient as using sight? There's been plenty of speculation on the topic, usually resulting in the answer that if <insert application vendor or platform vendor> waived their magic wand using a screen reader would be as efficient as sight. However, after spending several years considering this, and other human computer interaction issues related to screen reader use, I take a different view. My justification, whilst not exhaustive, is below. The first area where screen readers appear to fall short is in their ability to communicate semantics. Communication is all about communicating thoughts, concepts, states, etc., and communication between an interface for a piece of software and a user is no different in this respect. The main problem is that screen readers, through their use of speech and Braille, both of which are serialised forms of communication, use less physical variables to encode semantic
listen to it.There's roughly six variables that can be used to encode semantic content, and these are: * The position of something on the X, Y and Z axes * The position of something in time * The frequency of the physical wave, represented by things like color, pitch, etc. * The amplitude of the physical wave, or how strong it is Using a computer with sight typically takes advantage of five of these variables, whilst screen readers typically only use two. So, it will take longer to communicate the same semantic content using a screen reader than it will sight. To some extent this has supporting evidence from psychological studies in which the listening and reading speeds of the same person were compared. These studies found that the same individual could read something faster than they could
to be related to contextual priming.There are differences between individuals, which can account for why some screen reader users can listen to things faster than some people can read things, but within the same individual the evidence seems to indicate that listening to things is slower. This serialisation of semantic content, brought about by the smaller capacity of speech, also has implications for memory utilisation and cognitive workload. Studies involving Functional Magnetic Resonance Imaging of the cortex have shown greater activity in the cortical regions of the brain when listening to speech than when reading something. Not only is there activity on the left side of the cortex, in regions such as Brocha's Area and Wernicke's Area, which is present for both reading and listening, but listening to speech also produces activity in the right side of the cortex, which is thought
memory.In addition to the extra neurological activity associated with language processing, there is also a higher demand on short term working
more granular objects, such as paragraphs, tables, images, etc.As speech is temporary, one moment it is there, the next it is not, someone listening to speech has to remember more than someone reading something. It is not so easy to move back to a previously listened to word or sentence than it is to move back to a previously read word or sentence. Navigating by listening often involves listening to words, deciding whether they are the ones that are saught after, and if not, navigating some more and repeating the process. Another consideration are the distinctions between programatic focus, the mechanism used to shift attention with a screen reader, and visual attention. Screen readers utilise a mechanism of programatic focus to shift the user's attention between user interface elements. This means that a user's attention is only focused on a single point at once, something further compounded by a screen reader's use of serialised output. Whilst visual attention is usually focused on a single object, it can shrink and grow, similar to a zoom lens, to encompass more or less of an object. This ability to shift attention from a word to a paragraph and then onto the entire document provides a number of benefits for people reading documents. The most obvious benefit is the ability to not only navigate by word or line, but to navigate around the document based on
everything to be serialised.Whilst similar functionality is available in some screen readers for
a limited set of scenarios, this functionality is not as flexible as
the visual mechanism used to shift attention. The visual mechanism
can group granular objects together, such as a table proceeded by a
diagram, and can jump to those with very little requirement for
processing. In addition to granular navigation, attention can also
be shifted based on physical features, such as color or location,
which requires just the elements with those physical features to be
searched, as suggested by Treisman's Feature Integration Theory. As
far as I am aware, no equivalent functionality to this exists in a
screen reader. One key difference between programatic and visual
attention is that programatic attention can only be moved to fixed
points, whilst visual attention can be moved to any point or object.
The final difference worth mentioning is that attention is not just
limited to a single point in the visual field. Whilst there are
overt, indogenous, mechanisms to control visual attention through
moving the point of fixation, attention can also be focused in the
periphery of the visual field, through covert, indogenous,
mechanisms. This is a useful point, as it means that sighted people
can detect changes in the state of something that occur away from
their current point of fixation without the cognitive work involved
in moving the point of fixation So, I, for one, am beginning to form
the opinion that screen readers are not physically capable of
delivering the same levels of efficiency as sight can. This isn't to
say that blind people cannot gain the same level of efficiency, just
that it looks likely that they are unable to do this using a screen
reader. What is more, is that this is not the fault of a particular
application or platform vendor, as is often claimed, but more a
problem with the core concept of a screen reader, a concept that requires
Will
- [accessibleimage] Re: An antidote to CSUN
- From: John Panarese
- [accessibleimage] Re: An antidote to CSUN
- From: John Panarese