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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 need of new software development models

. understand the importance of user experience and usability in design
It has been said, “to err is human; to really screw up, you need a computer.”
Inefficient mechanical systems can waste couple cents on every widget you build, but
you can lose your entire company to bad information processes. The leverage that
software-based products---and the engineers that build them---have on your company
is enormous.
Sadly, our digital tools are extremely hard to learn, use, and understand, and they
often cause us to fall short of our goals. This wastes money, time, and opportunity. As
a business-savvy technologist/ technology-savvy businessperson, you produce
software-based products or consume them---probably both. Having better, easier-tolearn,
easier-to-use high-tech products is in your personal and professional best
interest. Better products don’t take longer to create, nor do they cost more to build.
The irony is that they don’t have to be difficult, but are so only because our process
for making them is old-fashioned and needs fixing. Only long-standing traditions
rooted in misconceptions keep us from having better products in today.
Consider a scenario: a website is developed of commerce system. The site is
aesthetically very beautiful, technically it has no flaw and it has wonderful animated
content on it. But if user is unable to find its desired information about the products or
even he is unable to find the product out of thousands of products, so what of it’s use.
It is useless from the business point of view.
Here are some facts and figures:
Users can only find information 42% of the time
– Jared Spool
62% of web shoppers give up looking for the item they want to buy online
– Zona Research
50% of the potential sales from a site are lost because people cannot find the item they
are looking for
– Forrester Research

40% of the users who do not return to a site do so because their first visit resulted in a
negative experience
– Forrester Research
80% of software lifecycle costs occur after the product is released, in the maintenance
phase - of that work, 80 % is due to unmet or unforeseen user requirements; only 20
% is due to bugs or reliability problems.
- IEEE Software
Around 63% of software projects exceed their cost estimates. The top four reasons for
this are:
– Frequent requests for changes from users
– Overlooked tasks
– Users' lack of understanding of their own requirements
– Insufficient user-analyst communication and understanding
- Communications of the ACM
BOO.com, a $204m startup fails
– BBC News
Poor commercial web sites will kill 80% of Fortune 500 companies within a decade
Jakob Nielsen
So all above given facts reveals that the product with the bad user experience deserve
to die!
All you can see that the real importance is of good interaction design. In above
example you saw that whole the systems which were developed technically very well
but failed just because of bad user experience, bad usability.

Scenario A
Sales Lost 0% 50%
Revenue Lost $0m $50m

$100m $50m
Actual Revenue

User Experience Good Bad
Revenue Potential $100m $100m
Scenario B

So, what if we design a system with good usability and good user experience. The
result will be satisfaction and happiness. People will be happy with your product and
they will buy your product, not only they will buy but also they will recommend
others for your product. And other people will also buy your product and this will
result a chain reaction. So, as you saw how your product can be successful if it
provides a good user experience.
Our discussion has a simple premise: if achieving the user’s goal is the basis of our
design process, the user will be satisfied and happy. If the user is happy, he will
gladly pay us money (and recommend that others do the same), and then we will be
successful as a business.
On the surface, this premise sounds quite obvious and straightforward: make the user
happy, and your products will be a success. Why then are so many digital products so
difficult and unpleasant to use? Why aren’t we all either happy or successful—or
Most digital products today emerge form the development process like a monster
emerging from a bubbling tank. Developers, instead of planning and executing with
their users in mind, end up creating technological solutions over which they
ultimately have little control. Like a mad scientists, they fail because they have not
imbued their creations with humanity.
We are mainly concerned with software, so, as we have stated earlier the definition of
software quality:
The extent to which a software product exhibits these characteristics

. Functionality

. Reliability

. Usability

. Efficiency

. Maintainability

. Portability
As you can see there are many characteristics to measure the quality of a software and
the usability is one of them.
In fact, we can understand the nature of usability in two aspects

. Strategic

. Tactical
Strategic aspect guides us to think about user interface idioms – in other words, the
way in which the user and the idiom interact.
Tactical aspect give us hints and tips about using and creating user interface idioms,
like dialog boxes and pushbuttons.
Integrating the strategic and tactical approaches is the key to designing effective user
interaction and interface. For example, there is no such thing as an objectively good
dialog box—the quality depends on the situation: who the user is and what his
background and goals are. Merely applying a set of tactical dictums makes user
interface creation easier, but it doesn’t make the end result better. Deep thoughts
about how users should interact with your system won’t improve the software, either.
What does work is maintaining a strategic sensitivity for how users actually interact

with specific software and having at your command a tactical toolbox to apply in any
particular situation.

Ignorance about users

It is a sad truth that the digital technology industry doesn’t have a good understanding
of what it takes to make users happy. In fact, most technology products get built
without much understanding of the users. We might know what market segment our
users are in., how much money they make, how much money they like to spend on
weekends, and what sort of cars they buy. May be we even having a vague idea what
kind of jobs they have and some of the major tasks that they regularly perform? But
does any of this tell us how to make them happy? Does it tell us how they will
actually use the product we are building? Does it tell us why they are doing whatever
it is they might need our product for, why they might want to choose our product over
our competitors, or how we can make sure they do? Unfortunately, it does not.

Conflict of Interest

A second problem affects the ability of vendors and manufacturers to make users
happy. There is an important conflict of interest in the world of digital product
development: the people who build the products—programmers—are usually also the
people who design them. Programmers are often required to choose between ease of
coding and ease of use. Because programmers’ performance is typically judged by
their ability to code efficiently and meet incredibly tight deadlines, it isn’t difficult to
figure out what direction most software-enabled products take. Just as we would
never permit the prosecutor in a legal trial to also adjudicate the case, we should make
sure that those designing a product are not the same people building it. It simply isn’t
possible for a programmer to advocate for the user, the business, and the technology
at the same time.

How can you achieve success?

The third reason that digital technology industry isn’t cranking out successful
products is that it has no reliable process for doing so. Or, to be more accurate, it
doesn’t have a complete process for doing so. Engineering departments follow—or
should follow—rigorous engineering methods that ensure the feasibility and quality of
the technology. Similarly, marketing, sales, and other business units follow their own
well-established methods for ensuring the commercial viability of new products.
What’s left out is a repeatable, analytical process for transforming and understanding
of users into products that both meet their needs and excite their imaginations.
While thinking about complex mechanical devices, we take for granted that they have
been carefully designed for use, in addition to being engineered. Most manufactured
objects are quite simple, and even complex mechanical products are quite simple
when compared to most software and software-enabled products that can sport in
excess of one million lines of code. Yet more software have never been undergone a
rigorous design process from a user-centered perspective. The current process of
determining what software will do and how it will communicate with the user is today
closely intertwined with its construction. Programmers, deep in their thoughts of
algorithms and code, “design” user interface the same way that miners “design” the
landscape with their cavernous pits and enormous tailing piles. The software interface
design process alternates between the accidental and the non-existent.

Many programmers today embrace the notion that integrating users directly into the
programming process on a frequent bias—weekly, or sometimes even daily—can
solve design problems. Although this has the salutary effect of sharing the
responsibility for design with the user, it ignores a serious methodological flaw: a
confusion of domain knowledge with design knowledge. Users although they might
be able to articulate the problems with an interaction, are not often capable of
visualizing the solutions to those problems. Design is a specialized skill, just like
programming. Programmer would never ask users to help them code; design problems
should be treated no differently.

Evolution of Software Development Process

Originally programmers did it all
In the early days of software industry smart programmers dreamed up useful software,
wrote and even tested it on their own. But as their businesses grew, the software
business and software business and software products became more complicated.

Managers brought order

Inevitably, professional managers were brought in. Good product managers
understand the market and competitors. They define software product by creating
requirements documents. Often, however, requirements are little more than a list of
features and managers find themselves having to give up features in order to meet

Testing and design became separate steps

As the industry matured, testing became a separate discipline and separate step in the
process. In the move from command-line to graphical user interface, design and
usability also became involved in the process, though often only at the end, and often
only affecting visual presentation. Today common practice includes simultaneous
coding and design followed by bug and user testing and then revision.

Design must precede the programming effort

A goal directed design approach to software development means that all decisions
proceed from a format definition of the user and his or her goals. Definition of the

Code/test ship
Code/test ship

user and user goals is the responsibility of the designer, thus design must precede


Design, according to industrial designer Victor Papanek, is the conscious and intuitive
effort to impose meaningful order. Cooper proposes a somewhat detailed definition:

. Understanding the user’s wants, needs, motivations, and contexts

. Understanding business, technical, and domain requirements and constraints

. Translating this knowledge into plans for artifacts whose form content, and
behavior is useful, usable and desirable, as well as economically viable and
technically feasible.
This definition applies across all design disciples, although the precise focus on form
versus content versus behavior varies by design discipline.
When performed using the appropriate methods, design can provide the missing
human connection in technological product. But clearly, the currently approach to the
design of digital products either isn’t working or isn’t happening as advertised.

Three dimensions of designs

Interaction design focuses on an area that traditional design disciplines do not often
explore: the design of behavior.
All design affects human behavior:
architecture is about how people use spaces
as much as it is about form and light. And
what would be the point of a poster if no one
acted on the information it presented?
However, it is only with the introduction of
interactive technologies – courtesy of the
computer – that the design of the behavior of
artifacts and how this behavior affects and
supports human goals and desires, has
become a discipline worthy of attention.
One way of making sense of he difference is
focus between interaction design and more
traditional design is through a historical
lens. In the first half of the twentieth century, designers focused primarily on form.
Later designers became increasingly concerned with meaning; for example, product
designers and architects introduced vernacular and retro forms in the 70s. The trend
continues today with retro-styled automobiles such as the PT Cruiser. Today,

User experts
initiate design code ship
Bug test
User test

information designers continue the focus on meaning to include the design of usable
Within the last fifteen years a growing group of designers have begun to talk about
behavior: the dynamic ways that software-enabled products interact directly with
These concerns (form, meaning and behavior) are not exclusive. Interactive products
must have each in some measure; software applications focus more on behavior and
form, with less demand on content; web sites and kiosks focus more on content and
form, with less sophisticated behaviors.

Definition interaction design

Simply put, interaction design is the definition and design of the behavior of artifacts,
environment, and systems, as well as the formal elements that communicate that
behavior. Unlike, traditional design disciplines, whose focus has historically been on
form and, more recently, on content and meaning, interaction design seeks first to
plan and describe how things behave and then, as necessary, to describe the most
effective form to communicate those behaviors.

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