CODI: Cornucopia of Disability Information

A Collection of General Notes on Accessibility

				 Appendix C

A Collection of General Notes on Accessibility

 (with specific comments in relation to Computers and Application Software)

What Is Meant by Accessibility?

Accessibility refers to the ability of products and environments to be used
by people.  In this particular context, accessibility is used to refer to the
ability of standard application software to be accessed and used by people
with disabilities.  Although the way people access the software may vary, the
program is accessible to an individual if the individual is able to use it to
carry out all of the same functions and to achieve the same results as
individuals with similar skills and training who do not have a disability.

Similarly, with software and operating systems, accessibility refers to the
ability of an individual to access and use the product in an effective and
efficient manner.  It does not have to be identical to the manner in which
somebody without a disability would use it, but it should provide equivalent
and efficient access.

Four Types of Strategies that Standard Product Manufacturers Can Use to Make
Their Products More Accessible

In looking at product accessibility, it is important to note that there are
different approaches to making products more accessible.  In any one product,
it may be necessary to use one or a combination of these approaches to
achieve the desired level of accessibility across all of the types of
disability.  Each of these approaches has advantages and disadvantages.  All
other things being equal, however, wherever possible, the first type, direct
accessibility, is the most advantageous.  These four approaches, in order of
desirability, are:

    1) Direct Accessibility

    2) Accessibility via Standard Options or Accessories (available
       separately from the manufacturer)

    3) Compatibility with Third-Party Assistive Devices

    4) Facilitation of Custom Modification

1) Direct Accessibility

For most types or degrees of impairment, there are simple and low cost (or no
cost) adaptations to product designs which can significantly increase their
accessibility and usefulness to individuals with functional impairments.  By
incorporating these design modifications into the initial product design, the
standard product can be more accessible directly "out of the box."  Direct
accessibility features can allow large numbers of people with mild to
moderate disabilities to directly use products as their colleagues without
disabilities do.  As mentioned previously, they also provide options or make
a product easier to use by all.


    1) Pre-Installed
       Always there; no need to find, buy, or install.

    2) Public Shared Products
       Will be present on products used in public or shared locations.

    3) Compatible
       If accessibility features are built directly into a standard
       product the access features will be automatically tested by
       third-party software or accessory manufacturers for
       compatibility with their products when they do their testing.

    4) No Additional Cost to User
       Product costs same for users with disabilities as those

    5) Less Stigma
       Particularly for older users, built in accessibility is much
       more acceptable than special aids or modifications and may be

    6) Easier to Use by All
       Products designed for people with reduced abilities are
       generally easier for everyone else to understand and use.


    1) Feasibility for Some Disabilities
       It is not practical or feasible to make some products directly
       accessible for people with some disabilities.  (e.g. not
       practical to build a braille display into every computer to
       allow access by deaf-blind users)


For application software manufacturers, a good part of maximizing the
accessibility of their software will be in being sure it is compatible with
the built-in or third-party accessibility features and aids.  This
compatibility includes not interfering with the invocation and operation of
the access features as well as cooperating with them by making key
information available only to the application program available to the access


A "MouseKeys" feature is now a standard part of all Apple Macintosh computers
shipped.  This feature, which can be invoked directly from the keyboard,
allows the user to move the cursor across the screen via the numeric keypad
rather than the mouse.  Individuals who do not have the motor control
necessary to operate a mouse can use this feature (which is built into all
Macintoshes) to access the Macintosh.  Because the feature is implemented as
an extension to the computer's operating system, it costs nothing to include
as part of the product.  Since "MouseKeys" became available, many able-bodied
users have found it useful as well because of its capability for precise
one-pixel positioning, which was not previously available.  (The MouseKeys
feature is now available for IBM computers running DOS, through a package
called "AccessDOS," available from IBM, and for Windows 3.0 and 3.1 through a
package called "Windows Access Utility," available from Microsoft.  (However,
in these cases, the access features are available as a separate package from
the standard operating system, and would therefore be examples of Type 2
accessibility, accessibility via standard option or accessory.)

Other, noncomputer examples of direct accessibility include MacDonald's, who
embossed braille characters on the tops of its soft drink cup covers along
with the letters labelling the pushdown buttons on the lid that indicate
whether the drink is diet, etc., and Proctor- Silex, who embossed braille
characters on the bottom of some of its bowls indicating the size (quarts) of
the bowl.

2) Accessibility via Standard Options or Accessories (available separately
from the manufacturer)


Sometimes it is not possible to design the standard product to make it
directly accessible for some disability populations.  Alternatives to
standard design may be identified, but offering all of them may not be
practical due to some alternatives being mutually exclusive, too expensive,
or awkward as a direct part of a standard product.

When this occurs, a strategy that manufacturers might use would be to make
these adaptations or alternatives available as standard options or
accessories from the manufacturer.  These may be special order items, or
preferably, items packed with the product.  These special features or
accessories should be listed and described in the standard documentation that
comes with the product.  They could also be listed in advertising for the
product.  (If the options or accessories are sold as separate products by the
manufacturer, the listing below would not apply, and the product would more
closely resemble the advantages/disadvantages list for third-party
compatibility found on the next page.)


    1) No Additional Cost to User
       If the manufacturer provides it free, the product would cost
       the same for users with disabilities as those without.

    2) Possible Compatibility Testing
       If the features are packaged directly with the standard
       product, they may be tested by third-party software or
       accessory manufacturers for compatibility with their products
       when they do their testing.

    3) Easier Implementation of Some Features
       Some features, such as braille overlays or software extensions
       that require substantial memory, may be easier to implement as
       options or accessories to the standard product.


    1) Must Be Installed
       No need to find or buy the feature, but it would have to be

    2) Public Shared Products
       May or may not be installed and therefore available on public
       use products.

    3) Possibly No Compatibility Testing
       If the features are not packaged directly with the standard
       product, they may very will not be known to or tested by third-
       party software or accessory manufacturers for compatibility
       with their products when they do their testing.


One reason that this approach is sometimes taken is because of
incompatibilities between various access features.  It may, in fact, not be
possible to have all of them co-reside simultaneously.  In this case, an
effective approach, particularly in the computer industry, would be to
package the various options as separate but included components in the
product when it is shipped.

If the access products/accessories are sold as separate products by a
manufacturer, they would be similar to a third-party product from the point
of view of the purchaser/user.  There may be some compatibility advantage to
the standard manufacturer's offering, since they have more detailed and
inside information on their product and product plans.  There may also be
more of a tendency for other software developers to test their software with
the standard manufacturer's offering.  On the other hand, third-party access
device manufacturers specialize in the design of aids for people with
disabilities or with particular disabilities, and may be able to design
access products with better functionality and compatibility with other
devices or strategies used by the person with a disability.  As a result, no
preference between access products marketed by the standard product
manufacturers and those marketed by third-party manufacturers can be drawn on
a general basis. Similarly, no preference between large and small third-party
manufacturers can be drawn.  Decisions in this area must be made on a
product-by-product basis.


Apple currently ships a screen enlargement utility called CloseView as a
standard part of its operating system package.  Because CloseView consumes a
fair amount of memory when loaded, it is not automatically installed in the
system when the computer is purchased (as the other disability access
features are).  It is, however, included as a part of the standard system
disks (along with a number of other optional system extensions which are not
disability-related).  Because it is packaged with the standard operating
system when it is sold, it has a much better chance of being compatible.
AccessDOS and the Windows Access Utilities cited above are also examples of
Type 2 accessibility features.  They are not, however, currently packaged
with the standard product.

3) Compatibility with Third-Party Assistive Devices


This involves designing the standard product in a manner that facilitates the
connection of third-party adaptive interfaces or assistive devices.  No
matter how sincere a manufacturer is about increasing the accessibility of
their products, there will always be individuals with severe or multiple
disabilities who will require special accessories in order to operate the
product.  Individuals who are deaf-blind, for example, who require dynamic
braille displays (costing thousands of dollars) cannot be directly
accommodated when building a computer which itself costs under a thousand
dollars.  While many accessibility options can be implemented in software,
such that they cause no significant increase in the product manufacturing
cost, the inclusion of a multi-thousand dollar braille display in every
computer in order to accommodate a small number of users is not efficient or
reasonable.  Similarly, an individual who can only use an eyegaze operated
keyboard, again costing a significant amount of money, could not reasonably
be accommodated by adding such an interface to standard product design.  In
these and other cases where substantial hardware or other manufacturing costs
would be involved, the most appropriate mechanism for providing accessibility
is through third-party special assistive devices.  In these cases, the best
strategy for standard product manufacturers is to maximize the compatibility
of their product with these assistive devices.


    1) Better Tailored Solutions
       Use of third-party access aids or special access software
       products which can be selected by a user to meet their
       particular needs and preferences can provide better access than
       a general built-in utility, especially for people with more
       severe disabilities.

    2) Familiar Interface
       Users who already have a communication or interface aid that
       they require for other purposes (and are familiar with) can use
       it to operate products which are compatible with it.

    3) Only Practical Approach for Some
       For some access strategies which involve expensive hardware,
       such as a dynamic Braille display or eye gaze keyboard, the use
       of third-party assistive devices (rather than building
       interfaces into each product) is the only practical approach.


    1) Must be Installed
       User must find, buy and install/attach the access interface.

    2) Additional Cost to User
       This approach requires that the user purchase the access
       interface or device separately.  However, if they have a severe
       disability, they may already have a general purpose interface

    3) Public Shared Products
       It is rarely possible to open up public access products
       (computers, information terminals, etc.) to install software or
       hardware needed by a user to access the product.  (An exception
       to this would be products which have a standard external port
       for connecting access aids.)

    4) Usually No Compatibility Testing
       Features that are not part of a standard product are usually
       not known to, much less tested for compatibility by, most
       third-party software or accessory manufacturers.


Built-in and third-party access approaches are not exclusive of each other.
It may well be appropriate for an individual to use built-in access features
for occasional use or basic access to public and shared products (computers
or information systems for example) that the individual runs across in daily
life yet use a more optimum access system from a third-party manufacturer
when they must work at a device for extended periods of time.

Assistive devices/interfaces from third-party manufacturers generally take
one of two forms.  They are usually either:

    a) programs, or accessories that are made specifically for
       interfacing or using the standard product or products like it
       (e.g., an eye gaze keyboard or screen reading program), or

    b) stand-alone aids (such as communication aids or writing
       systems) which can also function as interfaces to other

The use of third-party access products can be facilitated in a number of ways
including (but not limited to) :

      -   providing a standard external connection point where the
       product can be controlled from and where information sent to
       the display can also be found. by third-party products

      -   providing hooks or connection points in the operating system
       where third-party access software can tap into the information
       and control flow.

      -   not using display or control formats that are inaccessible
       to third-party access products without providing the
       information/control in an accessible format as well

      -   developing and documenting access strategies for new control
       or display formats which are currently inaccessible to third-
       party products.


Many people with physical disabilities cannot use standard computer
keyboards.  Some of these people would require more extensive modifications
than would be possible using the first two accessibility approaches
discussed.  Currently, there are assistive device manufacturers who make
alternative input devices to fit people with a variety of severe physical
disabilities.  However, the manufacturers of these assistive devices have
always had problems ensuring that the devices would work with standard,
commercially available computers.  As part of the effort by the computer
industry to cooperate with manufacturers of assistive devices, both IBM and
Microsoft Corporation now distribute an extension to their operating systems
(DOS and Windows) called "SerialKeys."  This extension allows people to
connect alternative input devices to the serial port of the standard personal
computer in a way which makes input to the serial port look like it is coming
directly from the standard keyboard and mouse.  In this fashion, the user
with a disability can completely access and control the computer and all of
its software from an alternate input system without touching the standard
keyboard or mouse.

4) Facilitation of Custom Modification

There are some cases where special circumstances require the custom
modifications of the product, either by the product manufacturer or a
third-party.  Standard product manufacturers can facilitate this process.


    1) Allows Custom Fitting of Solution
       Since this approach involves custom modification of products
       for a specific individual the solution can be designed to
       better meet their needs then either third-party or built-in
       access features.


    1) Must Be Installed
       User must find, buy and install/attach the access interface.

    2) Very High Cost
       This approach is the most expensive.  Unless it only involves
       relatively minor mechanical, electronic or programming
       modifications, the cost can be extremely high.

    3) Public Shared Products
       This approach does not help at all for access to public or
       shared products.

    4) No Compatibility Testing
       Testing for compatibility by third-party software or accessory
       manufacturers is not possible.


Leaving room for special attachments or labels, documenting hooks or places
to patch into hardware or software, publishing information on safe or
effective ways to modify products, or honoring warrantees for products which
have been modified for accessibility but where the modification did not
result in the problem.

The Best Approach

Of the four approaches to Accessible Design, the first type, direct
accessibility "from the box," is the best where it is possible.  It allows
the greatest access to products by persons with disabilities at the lowest
cost.  It also allows them to access products in public places where they
could not otherwise modify the products to meet their particular needs.  It
also removes the stigma of "special" aids or modifications.  This is
especially important for older users who do not want to be labeled "disabled"
even though their abilities are weakening.

It should also be noted that most of us become temporarily "disabled" in a
number of ways throughout our lives.  Sometimes it is by accident, such as a
broken arm or eye injury.  Sometimes it is by circumstance, such as operating
things in the dark where we can't see well, in loud environments (vacuuming
or teenagers) where we can't hear well, with things in our arms where we
can't reach well, when we're tired or on cold medication and can't think
well, etc.  Only those products which were designed to be more easily used
directly "from the box" (#1 above) will be of use to us then.  As mentioned
above, more accessible designs are also usually easier to use by everyone all
the time.  But only if the ease of use is directly built in.

There Are No "Accessible" Products

In all of the discussions above, you will note that nowhere was a product
described as being "accessible."  Products are more accessible or less
accessible.  We can also talk about the accessibility of a product.  However,
it is impossible or inaccurate to ever make the flat statement or judgement
that a product is "accessible" implying that it is accessible to all.  There
will always be individuals with severe and multiple physical, sensory, and
cognitive impairments who will not be able to use the product.

The corollary of this, of course, is that there is no set of measures that
someone can take that will make their product "accessible."  This is a
difficult concept and unwelcome news for those manufacturers who sincerely
want to make their products "accessible."  Manufacturers can make their
products more accessible or less accessible, but they cannot make them
"accessible" on an absolute scale.

In order to provide accessibility targets for manufacturers, however, a
number of "minimum accessibility standards" have been developed.  These
generally take the form of building codes or other regulations.  These are
the minimum levels of accessibility that must be achieved in order to be
acceptable according to some law or agency.  Manufacturers, however, should
view these as minimum accessibility standards, and strive to surpass them
where they can.  Individuals in the federal government who are interested in
purchasing accessible products may establish minimum accessibility standards.
However, their end goal is products that are as accessible as possible.
Manufacturers should therefore not view minimum accessibility standards as
Descriptions of accessibility.  Products that met the standards would not be
accessible.  They could be said to "meet XYZ accessibility standards," or
they may "meet or exceed all XYZ accessibility standards."

Thus, there are no totally accessible products.  The use of the term
accessible as a lone descriptor is misleading and confusing to those who try
to practice accessible (or universal) design.  Unfortunately, it is commonly
used this way today.  (Some suggested substitute words or usage might be:
more accessible, less accessible, minimal accessibility standard, minimally
acceptable accessibility, meets or meets and exceeds XYZ accessibility
standards, ADA accessible, GSA Guideline Accessible, accessible to an
individual, etc.)

Partial versus Complete Access for an Individual or Type of Disability

In designing products to be accessible, it is important to be sure that the
whole product is accessible.  Often, initial attempts at accessible design
are done piecemeal.  Accessible features are added where they are obvious
rather than as a result of looking at the product's overall accessibility.
The result can be a design which has accessible parts, but which is not as a
whole accessible or usable.  Access to half a product when the rest is
inaccessible is of little practical use.  In some cases, inspired by a desire
to address the needs of people with different disabilities, it is even
possible to design some parts of a device (such as the controls) to be more
accessible to one population and design another part of the product with
another disability in mind.  Unless the whole product is accessible to at
least one of these populations no-one is served. This is referred to as
Solomon's Trap*.

In most cases, it is possible with careful design to create products which
are simultaneously accessible to people with different impairments.  However,
where this is not possible, care should be taken to be sure that the entire
product is accessible to those disability populations that you are able to

Efficient Access

An important component of the Description of accessibility is that the
individual be able to use the product in a "similar yet efficient" fashion.
Because the individual with a disability may have different abilities from
someone without a disability, they will undoubtedly have to do things
somewhat differently.  In fact, someone who is deaf and someone who is blind
have differing abilities, and would have to access software in different ways
from each other.  Thus, the term similar does not imply that the person must
access in exactly the same manner.  They should, however, be able to access
the product in as similar and efficient a manner as possible.  The more
similar and efficient the access, the more accessible an environment or
product is.

Sometimes efficiency and similarity must be played off against each other.
In this case, efficiency is usually more important if the product requires
frequent and continual use.  Similarity is more important with products that
are infrequently used or only used for very short periods of time and where
there is not time pressure.

Accessibility Is a Continuous Function

Accessibility is not a yes/no proposition.  Even buildings or products which
meet accessibility codes vary in their accessibility.  The goal of accessible
design would not be to meet minimum accessibility measures, but to create a
product which is as accessible as possible and practical.

* Vanderheiden, G., and Vanderheiden, K.  (1991).  Accessible Design
  of Computer Products: Guidelines for the Design of Consumer Products
  to Increase Their Accessibility to People with Disabilities or Who
  Are Aging, page 17.  Madison, WI: Trace R&D Center, S-151 Waisman
  Center, 1500 Highland Avenue, ZIP 53705.