HUMAN COMPUTER INTERACTION

Disciplines Contribute to HCI

Human-computer Interaction is the kind of discipline, which is neither the
study of human, nor the study of technology, but rather the bridging
between those two.
So you always have to have one eye open to the question:
1. What can the technology do?
2. How can you build it?
3. What are the possibilities?
And one eye open to the question:
1. What are people doing and how would this fit in?
2. What they would do with it?

If you lose sight of either of those, you fail to design well. And of course
they require different ways of thinking. So the challenge is to keep
knowledge of both the technology and the people playing off against
each other in order to develop new things.

If you build something you need to consider not just ‘I’m building
something because I need to build it’, but ‘what effect is it going to have
on the way people work and the way people live?’

HCI understands the Complex Relationship between Human and

Computers, which are two distinct ‘Species’. Successful Integration is
dependent upon a better understanding of both Species. Hence HCI
borrows and establishes its roots in Disciplines concerned with both.
Academic Disciplines:

 Computer Science
o Develop programming languages, system architectures,
etc. of the computing systems
o Provides the technical foundation for the development of
computer systems, software, and algorithms.
o One of the main contributions of computer science to HCI
is to provide knowledge about the capabilities of technology
and ideas about how this potential can be harnessed. In
addition, computer scientists have been concerned about
developing various kinds of techniques to support software
design, development and maintenance.
 Engineering
o Provide faster and cheaper equipment
o Engineering is an applied science, which relies heavily on
model building and empirical testing.
o Design contributes creative skills and knowledge to this
process. In many respects the greatest influence of
engineering on HCI and subsequently on interface and system
development is through software engineering.
 Linguistics, Artificial Intelligence
o Linguistics is the scientific study of language (Lyons, 1970).
o Artificial Intelligence (AI) is concerned with the design of
intelligent computer programs which simulate different
aspects of intelligent human behavior. The relationship of
AI to HCI is mainly concerned with user’s needs when
interacting with an intelligent interface.
o Speech synthesis and recognition, natural language
processing, etc.
 Psychology
o Provide information about human mental capabilities
(e.g., memory, decision making)
o Psychology is concerned primarily with understanding
human behavior and the mental processes that underlie it.
To account for human behavior, cognitive psychology
has adopted the idea of information processing. Everything
we see, feel, touch, taste, smell and do is expressed in
terms of information processing. The objective cognitive
psychology has been to characterize these processes in
terms of their capabilities and limitations.
o Helps HCI professionals understand user needs, preferences,
and the psychological aspects of interface design.

 Ergonomics (Human Factors)

o Ergonomics (or human factors) is the scientific discipline
concerned with the understanding of interactions among
humans and other elements of a system, and the profession
that applies theory, principles, data and methods to design in
order to optimize human well-being and overall system
performance
o Provide information about human physical capabilities
o Ergonomics is a discipline that involves arranging the
environment to fit the person in it.
o The goal is to create a seamless and efficient interaction
 between users and computer systems while minimizing the risk
of discomfort, fatigue, and injury. Ergonomics in HCI considers
various aspects of the user interface, hardware, and software
to enhance usability and user satisfaction.
o The role of ergonomist is to translate information from the
above sciences into the context of design, whether for a car
seat or a computer system. The objective is to maximize an
operator’s safety, efficiency and reliability of performance, to
make a task easier, and to increase feelings of comfort and
satisfaction.

 Sociology
o Sociology is the study of social life, social change, and the
social causes and consequences of human behavior.
o Sociologists investigate the structure of groups, organizations,
and societies, and how people interact within these contexts.
o Informs HCI research on social aspects, digital inequalities, and
the impact of technology on communities.

Design Practices:
 Graphic Design
o Art of combining text and graphics and communicating an
effective message in design of posters, brochures, signs,
logos & other type of visual communications
 Product Design
o Process of planning the product's specification
o Product design is a multidisciplinary field that involves the
creation and development of new products or the improvement
of existing ones.
o It encompasses a range of activities, including
conceptualization, ideation, prototyping, and testing. The goal
of product design is to create products that are not only
functional and efficient but also aesthetically pleasing, user-
friendly, and marketable.
 Industrial Design
o Industrial design in Human-Computer Interaction (HCI) refers
to the application of design principles in the development of
physical interfaces, devices, and products that facilitate
human-computer interaction.
o The goal is to create user-friendly, aesthetically pleasing, and
ergonomic interfaces that enhance the overall user experience.
 o Aspects include overall shape of the object, colors, textures,
Sounds & product ergonomics
 Film Industry
o Multimedia is an interactive media and provides multiple ways to
represent information to the user in a powerful manner. It
provides an interaction between users and digital information. It
is a medium of communication.
People in HCI Business

 Interactive / Interaction Designers: People involved in the design of

all the interactive aspects of a product. Interaction designers in the
context of HCI specialize in creating the overall flow and interactions
within digital products, ensuring a seamless and intuitive user
experience. Interaction design is a crucial component of HCI,
focusing on how users interact with technology and optimizing those
interactions.

 Usability Engineers: People who focus on evaluating products using

usability methods and principles. Usability engineers in the field of
HCI are professionals who specialize in assessing and improving
the usability of digital products and systems. Usability engineering
focuses on creating interfaces that are easy to use, efficient, and
satisfying for the end-users.

 UI Designers: User Interface (UI) designers in the context of HCI

specialize in creating visually appealing and user-friendly interfaces
for digital products, systems, and applications. Their role is integral
to HCI, as the design of the user interface significantly influences
the overall user experience.

 UI Design Engineers: People who develop and model the end user
experience. UI (User Interface) design engineers in HCI are
professionals who specialize in implementing and bringing to life the
visual and interactive aspects of user interfaces. Their role involves
translating design concepts and specifications into functional and
aesthetically pleasing interfaces for digital products and systems.

 Web Designers: People who develop and create the visual design
of websites, such as layouts & animations

 Information Architects: People who come up with ideas of how to

plan and structure interactive products. They focus on organizing,
structuring, and labeling information to enhance the usability and
accessibility of digital products, systems, and websites.

 User Experience Designers: people who do all the above

 User Experience is
 An important concept in interaction design
 About how people feel about a product and their
pleasure and satisfaction when using it, looking at it,
holding it, opening it, closing it, etc.
 Examples: how smoothly a switch rotates, the sound
of a click, the touch of a button when pressing it

Activities in HCI Design

1. Identify needs and establish requirements
2. Develop alternative designs
3. Build interactive prototypes that can be communicated
and assessed
4. Evaluate what is being built throughout the process

 Users should be involved through the development of the

project

 Specific usability and user experience goals need to be

identified, clearly documented and agreed at the beginning of
the project

 Iteration is needed throughout the core activities

General Principles of HCI Design

 Making systems easy to use & learn
 Usability applies to all aspects of a system
Some principles to support usability are:

 Compatibility
 Ease of Learning
 Memorability
 Predictability
 Simplicity
 Flexibility
 Responsiveness
 Protection
 Invisible Technology
 Control
 WYSIWYG

Compatibility - Compatibility is a crucial aspect of usability, ensuring that

digital products or systems function seamlessly across various devices,
platforms, and contexts.
 User – know the user

 Product – can reduce both learning time & errors

Ease of learning
Ease of learning is a crucial aspect of usability, focusing on how quickly
users can understand and become capable in using a digital product or
system.
The system should be easy to learn so
that the user can rapidly start getting
some work done with the system

Memorability

Memorability in the context of usability refers to how easily users can

remember how to use a digital product or system after their initial
interactions. Designing for memorability is essential for creating user
interfaces that users can quickly recall and navigate without constant
reference to documentation or help.
Interfaces that have high memorability will be easier to learn and
use. Factors which affect memorability include

 Location: location in terms of memorability refers to the spatial

arrangement of elements within a user interface and how the
position or placement of elements influences users' ability to
remember and recall information. Properly utilizing the location
principle can enhance the memorability of a digital product.
 It will be easier to remember if a particular object is placed
in a consistent location, e.g., always putting the search box
in the upper right-hand corner of a Web page

 Logical grouping: Logical grouping is a design principle that

involves organizing elements or content in a way that makes
sense to users based on inherent relationships or similarities.
 By logically grouping related items together, designers enhance
the clarity and coherence of the user interface, making it easier
for users to navigate, understand, and interact with the system.

It will be easier to remember if things are grouped logically, e.g.,

putting related options together in a menu

 Conventions: conventions refer to established standards and

patterns that users are familiar with from their experiences with
various digital products. Conventional
objects and symbols will be easier to
remember, e.g., shopping cart symbol

Predictability
Refers to users' ability to anticipate and understand the outcome of their
interactions with a digital product or system. When a system is
predictable, users can make informed decisions, confidently navigate the
interface, and efficiently accomplish tasks.

Predictability involves a person’s expectations and his/her ability to

determine the results of actions ahead of time. It includes:

 Consistency – reinforce our associations and therefore increase

our ability to remember and predict outcomes and processes

 Generalizabilty – Help us use the knowledge we gathered from

previous experience and apply it to similar situations

 Familiarity – Familiarity, in the context of user interface design,

refers to the degree to which users recognize and are
accustomed to the elements, interactions, and patterns within a
digital product. e.g., familiar menu names and options help users
locate objects and functions more easily
  Conventions – Allow us to use our intuitions which are based on
previous experience and logic; if something is consistently done
in a particular way, it will eventually become the conventional
way of doing it.

Simplicity

Simplicity is a fundamental principle in usability that emphasizes the

importance of keeping user interfaces clear, straightforward, and easy to
understand.
If things are simple they will be easy to understand and thus easy
to learn and remember
It includes:
 Progressive disclosure – Progressive disclosure is a design
strategy that involves revealing information gradually,
presenting only the most essential features or content initially
and providing more details as users request or explore further.
Show the user only what is necessary.

 Constraints – constraints refer to limitations

or restrictions that impact the design process
and the final product.
While constraints may seem restrictive, they
play a crucial role in shaping the design,
setting boundaries, and guiding decision-
making.
It involve limiting the actions that can be
performed in a particular design.
Flexibility
 Allow more user control & accommodates variations in user
skill and preferences, i.e., give users choices

 Hardware
 Styles of interaction
 Data format

Responsiveness
Computer should respond immediately to a user’s input or inform the
user when long delays are unavoidable
Refers to a system or interface's
ability to adapt and provide a
seamless user experience
across different devices, screen
sizes, and resolutions.
Protection
 refers to ensuring that users
and their data are safeguarded
while interacting with a system
or interface.
 Protect users against
disastrous results of common
human error

Invisible Technology
 No need to know the technical
details
CONTROL
 Users should feel more in
control if the interface is
passive

WYSIWYG
 What you see is what you get
General Principles of HCI Design
 Principles which do / do not support user experience

 Satisfying
 Fun
 Enjoyable
 Entertaining
 Helpful
 Surprising
 Aesthetically pleasing
 Rewarding
 Supportive of creativity
 Emotionally fulfilling
 Boring
 Frustrating
 Annoying

 Principles are often in direct conflicts with one another. In order to

make the trade-offs intelligently, a thorough understanding of the
intended users is required

 These principles are very general and designers may not know
how to apply them directly