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Human Computer Interaction

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As the aim of this lecture is to introduce you the study of Human Computer
Interaction, so that after studying this you will be able to:

. Understand the role of information architecture

. Understand the importance of accessibility


A web site is a collection of interconnected systems with complex dependencies. A
single link on a page can simultaneously be part of the site's structure, organization,
labeling, navigation, and searching systems. It's useful to study these systems independently,
but it's also crucial to consider how they interact. Reductionism will not
tell us the whole truth.
Metadata and controlled vocabularies present a fascinating lens through which to
view the network of relationships between systems. In many large metadata-driven
web sites, controlled vocabularies have become the glue that holds the systems
together. A thesaurus on the back end can enable a more seamless and satisfying user
experience on the front end.
In addition, the practice of thesaurus design can help bridge the gap between past and
present. The first thesauri were developed for libraries, museums, and government
agencies long before the invention of the World Wide Web. As information architects
we can draw upon these decades of experience, but we can't copy indiscriminately.
The web sites and intranets we design present new challenges and demand creative
When it comes to definitions, metadata is a slippery fish. Describing it as "data about
data" isn't very helpful. The following excerpt from Dictionary.com takes us 2 little
In data processing, meta-data is definitional data that provides information about or
documentation of other data managed within an application or environment. For
example, meta-data would document data about data elements or attributes (name,
size, data type, etc) and data about records or data structures (length, fields, columns,
etc) and data about data (where it is located, how it is associated, ownership, etc.).
Meta-data may include descriptive information about the context, quality and
condiČtion, or characteristics of the data.
While these tautological explanations could lead us into the realms of epistemology
and metaphysics, we won't go there. Instead, let's focus on the role that metadata plays
in the practical realm of information architecture.
Metadata tags are used to describe documents, pages, images, software, video and
audio files, and other content objects for the purposes of improved navigation and
retrieval. The HTML keyword meta tag used by many web sites provides a simple
example. Authors can freely enter words and phrases that describe the content. These

keywords are not displayed in the interface, but are available for use by search
<meta name="keywords" content="information architecture, content management,
knowledge management, user experience">
Many companies today are using metadata in more sophisticated ways. Leveraging
content management software and controlled vocabularies, they create dynamic meta
data-driven web sites that support distributed authoring and powerful navigation. This
metadata-driven model represents a profound change in how web sites are created and
managed. Instead of asking, "Where do I place this document in the taxaonomy?" we
can now ask, "How do I describe this document?" The software and vocabulary
systems take care of the rest.

Controlled Vocabularies

Vocabulary control comes in many shapes and sizes. At its most vague, a controlled
vocabulary is any defined subset of natural language. At its simplest, a controlled
vocabulary is a list of equivalent terms in the form of a synonym ring, or a list of
preferred terms in the form of an authority file. Define hierarchical relationships
between terms (e.g., broader, narrower) and you've got a classification scheme. Model
associative relationships between concepts (e.g., see also, see related) and
Since a full-blown thesaurus integrates all the relationships and capabilities of the
simpler forms, let's explore each of these building blocks before taking a close look at
the "Swiss Army Knife" of controlled vocabularies.
Classification schemes can also be used in the context of searching. Yahoo! does this
very effectively. Yahoo!'s search results present "Category Matches," which
reinforces users' familiarity with Yahoo!'s classification scheme.
Pel$:find Hamsters in Yahoo! Pets
Bizarre Humor> Hamster Dance
Humor> Hamsters
Rodents> Hamsters
List "hamsters"_by location
The above are Category Matches at Yahoo!
The important point here is that classification schemes are not tied to a single view or
instance. They can be used on both the back end and the front end in all sorts of ways.
We'll explore types of classification schemes in more detail later in this chapter, but
first let's take a look at the "Swiss Army Knife" of vocabulary control, the thesaurus.


Dictionary.com defines thesaurus as a "book of synonyms, often including related and
contrasting words and antonyms." This usage harkens back to our high school English
classes, when we chose big words from the thesaurus to impress our teachers.

Our species of thesaurus, the one integrated within a web site or intranet to improve
navigation and retrieval, shares a common heritage with the familiar reference text but
has a different form and function. Like the reference book, our thesaurus is a semantic
network of concepts, connecting words to their synonyms, homonyms, antonyms,
broader and narrower terms, and related terms.
However, our thesaurus takes the form of an online database, tightly integrated with
the user interface of a web site or intranet. And while the traditional thesaurus helps
people go from one word to many words, our thesaurus does the opposite. Its most
important goal is synonym management, the mapping of many synonyms or word
variants onto one preferred term or concept, so the ambiguities of language don't
prevent people from finding what they need.
So, for the purposes of this book, a thesaurus is:
A controlled vocabulary in which equivalence, hierarchical, and associative
relationships are identified for purposes of improved retrieval..
--ANSI/NISO Z39.19 -1993 (R1998). Guidelines for the Construction, Format, and
Management of Monolingual Thesauri.
A thesaurus builds upon the constructs of the simpler controlled vocabularies,
modeling these three fundamental types of semantic relationships.
Each preferred term becomes the center of its own semantic network. The equivalence
relationship is focused on synonym management. The hierarchical relationship
enables the classification of preferred terms into categories and subcategories. The
associative relationship provides for meaningful connections that are not handled by
the hierarchical or equivalence relationships. All three relationships can be useful in
different ways for the purposes of information retrieval and navigation.

44.1 Accessibility

Accessibility is a general term used to describe the degree to which a system is usable
by as many people as possible without modification. It is not to be confused with
usability which is used to describe how easily a thing can be used by any type of user.
One meaning of accessibility specifically focuses on people with disabilities and their
use of assistive devices such as screen-reading web browsers or wheelchairs. Other
meanings are discussed below.
Accessibility is strongly related to universal design in that it is about making things as
accessible as possible to as wide a group of people as possible. However, products
marketed as having benefited from a Universal Design process are often actually the
same devices customized specifically for use by people with disabilities. It is rare to
find a Universally Designed product at the mass-market level that is used mostly by
non-disabled people.
The disability rights movement advocates equal access to social, political and
economic life which includes not only physical access but access to the same tools,
organisations and facilities which we all pay for.
A typical sign for wheelchair accessibilityAccessibility is about giving equal access to
While it is often used to describe facilities or amenities to assist people with
disabilities, as in "wheelchair accessible", the term can extend to Braille signage,
wheelchair ramps, audio signals at pedestrian crossings, walkway contours, website
design, and so on.

Various countries have legislation requiring physical accessibility:
In the UK, the Disability Discrimination Act 1995 has numerous provisions for
In the US, under the Americans with Disabilities Act of 1990, new public and private
business construction generally must be accessible. Existing private businesses are
required to increase the accessibility of their facilities when making any other
renovations in proportion to the cost of the other renovations. The U.S. Access Board
is "A Federal Agency Committed to Accessible Design for People with Disabilities."
Many states in the US have their own disability laws.
In Ontario, Canada, the Ontarians with Disabilities Act of 2001 is meant to "improve
the identification, removal and prevention of barriers faced by persons with

Introduction to Web Accessibility

Most people today can hardly conceive of life without the Internet. It provides access
to information, news, email, shopping, and entertainment. The Internet, with its ability
to serve out information at any hour of the day or night about practically any topic
conceivable, has become a way of life for an impatient, information-hungry
generation. Some have argued that no other single invention has been more
revolutionary since that of Gutenberg's original printing press in the mid 1400s. Now,
at the click of a mouse, the world can be "at your fingertips"—that is, if you can use a
mouse... and if you can see the screen... and if you can hear the audio—in other
words, if you don't have a disability of any kind.
Before focusing on the challenges that people with disabilities face when trying to
access web content, it makes more sense to discuss the ways in which the Internet
offers incredible opportunities to people with disabilities that were never before
possible. The web's potential for people with disabilities is truly remarkable.
The Web Offers Unprecedented Opportunities
The Internet is one of the best things that ever happened to people with disabilities.
You may not have thought about it that way, but all you have to do is think back to
the days before the Internet was as ubiquitous as it is today to see why this is so.
For example, without the Internet, how did blind people read newspapers? The answer
is that they mostly didn't. At best, they could ask a family member or friend to read
the newspaper to them. This method works, but it makes blind people dependent upon
others. They could never read the newspaper themselves. You might think that
audiotapes or Braille printouts of newspapers could offer a reasonable solution, but
both options are expensive and slow compared to the rate at which publishers create
and distribute newspapers. Blind people wouldn't receive the news until after it was
no longer new. Not only that, but a Braille version of the Sunday New York Times
would be so big and bulky with the extra large and thick Braille embossed paper that
you'd practically have to use a forklift to move it around. None of these methods of
reading newspapers are ideal. They're too slow, expensive, and too dependent upon
other people.
With the advent of the World Wide Web, many newspapers now publish their content
electronically in a format that can be read by text-to-speech synthesizer software

programs (often called "screen readers") used by the blind. These software programs
read text out loud so that blind people can use computers and access any text content
through the computer. Suddenly, blind people don't have to rely on the kindness of
other people to read the newspaper to them. They don't have to wait for expensive
audio tapes or expensive, bulky Braille printouts. They simply open a web browser
and listen to their screen reader as it reads the newspaper to them, and they do it when
they want to do it. The Internet affords a whole new level of independence and
opportunity to blind people. When you understand the impact that the Internet can
have in the lives of blind people, the concept of web accessibility takes on a whole
new level of significance.
Similarly, people with motor disabilities who cannot pick up a newspaper or turn its
pages can access online newspapers through their computer, using certain assistive
technologies that adapt the computer interface to their own disabilities. Sometimes the
adaptations are crude, such as having the person place a stick in the mouth, and to use
that stick to type keyboard commands. In other cases, the adaptations are more
sophisticated, as in the use of eye-tracking software that allows people to use a
computer with nothing more than eye movements. People with tremors may use a
special keyboard with raised ridges in-between the keys so that they can place their
hand down on the keyboard and then type the letters, rather than risk typing the wrong
keys. Most of these people would not be able to use a mouse with much accuracy.
Regardless of the level of sophistication, many of these adaptations have one thing in
common: they make use of the keyboard, or emulate the use of a keyboard, rather
than the use of a mouse. As with people who are blind, the Internet allows people with
motor disabilities to access information in ways that they never could before.
People who are deaf always had the possibility of reading newspapers on their own,
so it may seem that the Internet does not offer the same type of emancipation that it
does to those who are blind or to those with motor disabilities, but there are a few
cases in which the Internet can still have a large impact. For example, they can read
online transcripts of important speeches, or view multimedia content that has been
fully captioned.
Falling Short of the Web's Potential
Despite the Web's great potential for people with disabilities, this potential is still
largely unrealized. Where can you find web-based video or multimedia content that
has been fully captioned for the deaf? What if the Internet content is only accessible
by using a mouse? What do people do if they can't use a mouse? And what if web
developers use all graphics instead of text? If screen readers can only read text, how
would they read the graphics to people who are blind? As soon as you start asking
these types of questions, you begin to see that there are a few potential glitches in the
accessibility of the Internet to people with disabilities. The Internet has the potential
to revolutionize disability access to information, but if we're not careful, we can place
obstacles along the way that destroy that potential, and which leave people with
disabilities just as discouraged and dependent upon others as before.
People with Disabilities on the Web
Though estimates vary, most studies find that about one fifth (20%) of the population
has some kind of disability. Not all of these people have disabilities that make it
difficult for them to access the Internet. For example, a person whose legs are
paralyzed can still navigate a web site without any disability-related difficulty. Still, if
only half—or even a quarter—of these individuals have disabilities that affect their
ability to access the Internet, this is a significant portion of the population. Businesses
would be unwise to purposely exclude 20, 10 or even 5 percent of their potential

customers from their Web sites. Schools, universities, and government entities would
be not only unwise, but, in many countries, they would also be breaking the law if
they did so.
Each of the major categories of disabilities require certain types of adaptations in the
design of the web content. Most of the time, these adaptations benefit nearly
everyone, not just people with disabilities. For example, people with cognitive
disabilities benefit from illustrations and graphics, as well as from properly-organized
content with headings, lists, and visual cues in the navigation. Similarly, though
captioned video content is meant to benefit people who are deaf, it can also benefit
those who do not have sound on their computers, or who do not want to turn the
sound on in public places such as libraries, airplanes, or computer labs.
Occasionally, Web developers must implement accommodations that are more
specific to people with disabilities. For example, developers can add links that allow
blind users or people with motor disabilities who cannot use a mouse to skip past the
navigational links at the top of the page. People without disabilities may choose to use
this feature as well, but they will usually ignore it. In almost every case, even these
disability-specific adaptations can be integrated into the site's design with little or no
impact to its overall visual "look and feel." Unfortunately, too many web developers
are convinced that the opposite is true. They worry that their sites will become less
appealing to their larger audience of people without disabilities. This faulty perception
has led to countless circular debates, that tend to cause unnecessary friction between
web designers and people with disabilities.
From the perspective of people with disabilities, inaccessible web content is an
obstacle that prevents them from participating fully in the information revolution that
has begun unfolding on the Internet. To them, it is a matter of basic human rights.
When web developers truly understand this perspective, most of them realize the
importance of the issue, and are willing to do what they can to make their Web
content more accessible.
Comprehensive Solutions
There are two key components to any effort to achieve web accessibility:

. Commitment and accountability

. Training and technical support
Either of these by itself is insufficient.
Commitment and accountability
Awareness. The foundation of any kind of commitment to web accessibility is
awareness of the issues. Most Web developers are not personally opposed to the
concept of making the Internet accessible to people with disabilities. In fact, most
accessibility errors on web sites are the result of ignorance, rather than malice or
apathy. A large proportion of developers have simply never even thought about the
issue. Even if they have heard of web accessibility, they may not understand what's at
stake. Their ignorance leads them to ask questions such as, "Why would a blind
person want to access the Internet?" After hearing an explanation of the ways in
which blind people can access the Internet and the reasons why they have difficulties
with some sites, most of these same developers understand the importance of the
issue, and most are willing to do something about it, at least in the abstract.
Leadership. Understanding the issues is an important first step, but it does not solve
the problem, especially in large organizations. If the leadership of an organization

does not express commitment to web accessibility, chances are low that the
organization's web content will be accessible. Oftentimes, a handful of developers
make their own content accessible while the majority don't bother to, since it is not
expected of them.
Policies and Procedures. Even when leaders express their commitment to an idea, if
the idea is not backed up by policies, the idea tends to get lost among the day-to-day
routines. The best approach for a large organization is to create an internal policy that
outlines specific standards, procedures, and methods for monitoring compliance with
the standards and procedures. For example, an organization's policy could be that
Web developers will create content that complies with the web Content Accessibility
Guidelines of the W3C, that no content is allowed to go live on the web site until it
has been verified to meet this standard, and that the site will be re-examined quarterly
for accessibility errors. This example won't fit every situation or every organization,
but it does at least provide a simplified theoretical model from which to create
standards, procedures, and monitoring methods within organizations.
Training and technical support
Sometimes web developers fear that it is more expensive and time-consuming to
create accessible web sites than it is to create inaccessible ones. This fear is largely
untrue. On a page-by-page basis, the extra time required by a knowledgeable
developer to make the content accessible is so minimal as to be almost negligible.
Once developers know the concepts, implementing them becomes second-nature, and
does not add significantly to the total development time.
However, it does take time to become a knowledgeable developer. A developer can
learn the basics of Web accessibility in just a few days, but, as with any technical
skill, it often takes months to internalize the mindset as well as the techniques.
Organizations should ensure that their developers have access to training materials,
workshops, books, or courses which explain the details of accessible web design.
Some of these resources are available for free, such as the WebAIM web site.
However, not everyone learns best in an online environment. Sometimes the best
approach is to invite an outside consultant to provide training through presentations,
workshops, or one-on-one tutoring.
Ongoing technical support can be offered through outside consultants, discussion
groups, internal workshops, classes or other methods. Some organizations have set up
their own internal discussion groups to provide a forum for talking about accessibility
issues. If a developers forum already exists at an organization, it may be unnecessary
to create a new one specifically for accessibility if the existing one can serve the same
purpose. The WebAIM forum consists of people from all over the world who are
interested in Web accessibility issues, many of whom are highly knowledgeable about
the topic and willing to share their knowledge with others.
The web offers so many new opportunities to people with disabilities that are
unavailable through any other medium. It provides a method for accessing
information, making purchases, communicating with the world, and accessing
entertainment that does not depend on the responsiveness of other people. The
Internet offers independence and freedom. But this independence and freedom is only
partially a reality. Too many web sites are not created with web accessibility in mind.

Whether purposefully or not, they exclude the segment of the population that in many
ways stands to gain the most from the Internet. Only by committing to accessibility
and providing for accountability, training, and technical assistance, can the web's full
potential for people with disabilities become a reality.

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