What is math accessibility?
We often use the terms "access" and "accessible" in various
ways, depending upon the context of our discussion. It is not uncommon to
hear someone talk about a presentation being "accessible," for example,
meaning that the content of the presentation was easy to comprehend or
perhaps that the listener meant he or she could identify with the speaker's
points.
According to the Merriam-Webster
Online Dictionary, the term access can be defined as "permission,
liberty, or ability to enter, approach, communicate with, or pass to and
from," while the related term accessible is given a definition which
includes "capable of being used or seen." These basic definitions are useful
for building an understanding of the term accessibility as is relates
to people with disabilities, and specifically to the concept of what we call
"math
accessibility."
Many times, the terms
"accessible" and "accessibility" are used in the
discussion of civil rights for people with disabilities. Initially these
terms were used to define the ability of people with physical disabilities
who use wheelchairs to enter and navigate within a building. Thus, a structure was considered to be "accessible" when it had certain
design features allowing unrestricted access for someone using a
wheelchair, such as ramps and elevators.
Of course, opinions on what accessibility really means in
practice can differ from one person to the next. So one of the first
attempts to define accessibility--at least as far as buildings are
concerned--was begun in 1959
by the
President's Committee on Employment of the Physically Handicapped, which
commissioned the creation of the first national accessibility standard by
the American National Standards Institute
(ANSI), a private standard-setting body. The resulting standard,
ANSI A117.1,
was first published in 1961 and quickly became cited as a mandatory requirement through reference in
State and
Federal law.
In addition to the ANSI standard, the Federal government
later invested itself with the power to create uniform building
accessibility standards in 1968 with the passage of the
Architectural
Barriers Act. Congress passed this Act "to insure
that certain buildings financed with Federal funds are so designed and
constructed as to be accessible to the physically handicapped." This
legislation authorized the executive branch "to prescribe such standards for
the design, construction, and alteration of buildings...subject to this Act
as may be necessary to insure that physically handicapped persons will have
ready access to, and use of such buildings." These standards, and many other
accessibility standards mandated by the Federal government since that time, are now
published under the authority of the
United States Access Board.
It is vital to understand that, just as buildings can be made
accessible or inaccessible by the inclusion or exclusion of certain design
principles, this same concept of accessibility has been applied to
the communication of information. For instance, under Federal law, all
televisions produced in the US after July 1993 which are 13 inches or larger
are required to have built-in closed-caption decoders for the hearing
impaired. This way, audio information which is inaccessible to someone who
cannot hear, can be made accessible through this technological design
feature.
The concept of information accessibility in computer
environments has more recently become a critical area of access for people with
disabilities. To deal with the need for accessibility on the Internet, the
World Wide Web Consortium (W3C) initiated
the Web Accessibility Initiative and released a recommendation called the
Web Content Accessibility
Guidelines in 1999. Not long thereafter, the Federal government released its own
set of Electronic and Information Technology Standards through the Access
Board as part of the regulations enforcing
Section 508 of the
Rehabilitation Act. These standards set baseline access criteria for web
pages produced by the federal government, and also
provided accessibility standards for technologies such as computer software, fax machines, and office copiers.
One of the fundamental principles of information
accessibility is expressed in the language of the Section 508 statute: that
individuals with disabilities must "have access to and use of information
and data that is comparable to the access to and use of the information and
data by such members of the public who are not individuals with
disabilities." Comparable access to and use of information in
electronic formats has been understood to mean that individuals with
disabilities who use assistive technologies such as screen enlargement,
synthetic speech, or speech dictation will be able to effectively utilize
and benefit from these electronic formats on par with the way that people without
disabilities use standard computer displays, keyboards and mice.
The concept of accessibility to mathematical information
must also be understood within the framework of comparable access.
Although basic mathematical information can be expressed using the
alphanumeric characters found on the common computer keyboard, one does not
have to go very far in complexity of math to run into problems. The common
usage of elements such as superscripts and square root symbols, for
instance, will typically be inaccessible to a blind person using synthetic
speech unless this information is properly imbedded in the digital content
to provide for accessibility.
The current lack of comparable access to math occurs because the
equations found in electronic information such as in computer software or on
a web page are typically created using graphical image files, or digital
pictures, of math equations. Images such as this can only be viewed and
interpreted with human eyes, so that people who depend upon computer technology
to synthetically read out loud the information on the screen will be unable to
access these mathematical expressions. Thus, in this case, individuals who are
blind, have a significant learning disability affecting reading, or have any other
type of disability requiring them to use screen reading technology will have absolutely
no access to this information.
One of the stopgap measures sometimes used to provide a
degree of access to mathematical information is to include "alternative
text" for graphics of math equations. In this case, the producer of the
electronic format containing a math equation as a graphical image file will
also provide a literary expression of the equation as a person might read it
in his or her native tongue. While this does meet the
baseline accessibility standard for access to common types of graphical information, this
practice does not result in a level of access which is truly comparable to
that of a person without a disability, who can view the equation in a
two-dimensional form on
the screen and interpret its proper meaning. Although this
technique does provide a person with a disability some information
that can be accessed with assistive technology, it is clearly inferior to
the level of access that the non-disabled person would have through standard
means, and therefore falls short of the
legislative intent of Section 508 for comparable access.
More recently, the accessibility community has adopted a
standards-based approach to math accessibility using
Mathematical Markup Language, or MathML,
which goes much further toward true comparable access to math. MathML is an XML
application for describing mathematical notation and capturing both its
structure and content. Using MathML enables mathematics to be served, received,
and processed in digital environments such as the World Wide Web, just as HTML
has enabled this functionality for literary text. Furthermore, using MathML
provides for a standard approach to content tagging and information structure
which can make mathematical information available to assistive technology in a
way that is comparable to standard visual access.
One of the most important aspects of using MathML, however, is
that it provides the capability to move beyond considerations of accessibility
as an "add on" or "alternative" approach to creating universally designed math
content, which has benefits for all learners--not just students with
disabilities. The term "universal
design" means "a concept or philosophy for designing and delivering products
and services that are usable by people with the widest possible range of
functional capabilities, which include products and services that are directly
accessible (without requiring assistive technologies) and products and services
that are interoperable with assistive technologies." When MathML is used to
author digital math materials, the resulting content can be universally used by
all people. Math materials created using MathML can be transparently rendered in
many ways depending upon the user's needs. It can be displayed on a computer
screen, printed on paper, enlarged, spoken by synthetic speech computer
applications or made into braille.
Using MathML provides not only comparable access to math
content for students with disabilities, but gives all students access to
rich math content with support for enhanced learning delivery modes.
Equations authored in MathML can be displayed onscreen with highlighting
that moves in sync with synthetic speech, providing students with
multi-modal visual and aural learning support. MathML also provides the
capacity to allow students to visually and aurally "walk through" various
parts of an extended equation at their own pace. These capabilities will aid
all students as they learn math concepts.
So, to go back to our Webster definition of the term
accessible, with MathML, math can truly be made "capable of being used or
seen" by all people--even by those who cannot "see" in the traditional sense of the
word, but who depend upon assistive technology to access information. And
just as physical structures are made accessible by the inclusion of
standardized design features, documents containing mathematical information
can now be made accessible by using MathML, a standardized digital design
feature providing unrestricted comparable access to math for people with--and
without--disabilities. Finally, the universal design features of math
content authored with MathML will provide enhanced learning benefits to all
students.
Further Information and Resources
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