LECTURE NOTES
ON
HUMAN COMPUTER INTERACTION
IV B.TECH-I SEM (R15)
PREPARED BY
B PRAVALLIKA
Assistant Professor
INFORMATION TECHNOLOGY
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
Dundigal – 500 043, Hyderabad
1
, UNIT-I
INTRODUCTION
Human–computer interaction (HCI), alternatively man–machine interaction (MMI) or
computer–human interaction (CHI) is the study of interaction between people (users) and
computers.
• With today's technology and tools, and our motivation to create really effective and
usable interfaces and screens, why do we continue to produce systems that are inefficient
and confusing or, at worst, just plain unusable? Is it because:
1. We don't care?
2. We don't possess common sense?
3. We don't have the time?
4. We still don't know what really makes good design?
DEFINITION
• "Human-computer interaction is a discipline concerned with the design, evaluation and
implementation of interactive computing systems for human use and with the study of
major phenomena surrounding them."
GOALS
• A basic goal of HCI is
– to improve the interactions between users and computers
– by making computers more usable and receptive to the user's needs.
• A long term goal of HCI is
– to design systems that minimize the barrier between the human's cognitive
model of what they want
– to accomplish and the computer's understanding of the user's task
WHY IS HCI IMPORTANT
• User-centered design is getting a crucial role!
• It is getting more important today to increase competitiveness via HCI studies (Norman,
1990)
• High-cost e-transformation investments
• Users lose time with badly designed products and services
• Users even give up using bad interface
– Ineffective allocation of resources
2
,DEFINING THE USER INTERFACE
• User interface, design is a subset of a field of study called human-computer interaction
(HCI).
• Human-computer interaction is the study, planning, and design of how people and
computers work together so that
a person's needs are satisfied in the most effective way.
• HCI designers must consider a variety of factors:
– what people want and expect, physical limitations and abilities people possess,
--how information processing systems work,
– what people find enjoyable and attractive.
– Technical characteristics and limitations of the computer hardware and software
must also be considered.
• The user interface is to
– the part of a computer and its software that people can see, hear, touch, talk
to, or otherwise understand or direct.
• The user interface has essentially two components: input and output.
• Input is how a person communicates his / her needs to the computer.
– Some common input components are the keyboard, mouse, trackball,
one's finger, and one's voice.
• Output is how the computer conveys the results of its computations and
requirements to the user.
– Today, the most common computer output mechanism is the display
screen, followed by mechanisms that take advantage of a person's auditory
capabilities: voice and sound.
• The use of the human senses of smell and touch output in interface design still
remain largely unexplored.
• Proper interface design will provide a mix of well-designed input and output
mechanisms that satisfy the user's needs, capabilities, and limitations in the most
effective way possible.
• The best interface is one that it not noticed, one that permits the user to focus on the
information and task at hand, not the mechanisms used to present the information and
perform the task.
3
, THE IMPORTANCE OF GOOD DESIGN
With today's technology and tools, and our motivation to create really effective and usable
interfaces and screens, why do we continue to produce systems that are inefficient and
confusing or, at worst, just plain unusable? Is it because:
• We don't care?
• We don't possess common sense?
• We don't have the time?
• We still don't know what really makes good design?
• But we never seem to have time to find out what makes good design, nor to properly
apply it. After all, many of us have other things to do in addition to designing interfaces
and screens.
• So we take our best shot given the workload and time constraints imposed upon us. The
result, too often, is woefully inadequate.
• Interface and screen design were really a matter of common sense, we developers would
have been producing almost identical screens for representing the real world.
• Example bad designs
– Closed door with complete wood
– suggestion : glass door
THE IMPORTANCE OF THE USER INTERFACE
A well-designed interface and screen is terribly important to our users. It is their
window to view the capabilities of the system.
It is also the vehicle through which many critical tasks are presented. These tasks
often have a direct impact on an organization's relations with its customers, and its
profitability.
A screen's layout and appearance affect a person in a variety of ways. If they are
confusing and inefficient, people will have greater difficulty in doing their jobs and
will make more mistakes.
Poor design may even chase some people away from a system permanently. It can
also lead to aggravation, frustration, and increased stress.
The Benefits of Good Design
Poor clarity forced screen users to spend one extra second per screen.
o Almost one additional year would be required to process all screens.
o Twenty extra seconds in screen usage time adds an additional 14 person
years.
4
ON
HUMAN COMPUTER INTERACTION
IV B.TECH-I SEM (R15)
PREPARED BY
B PRAVALLIKA
Assistant Professor
INFORMATION TECHNOLOGY
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
Dundigal – 500 043, Hyderabad
1
, UNIT-I
INTRODUCTION
Human–computer interaction (HCI), alternatively man–machine interaction (MMI) or
computer–human interaction (CHI) is the study of interaction between people (users) and
computers.
• With today's technology and tools, and our motivation to create really effective and
usable interfaces and screens, why do we continue to produce systems that are inefficient
and confusing or, at worst, just plain unusable? Is it because:
1. We don't care?
2. We don't possess common sense?
3. We don't have the time?
4. We still don't know what really makes good design?
DEFINITION
• "Human-computer interaction is a discipline concerned with the design, evaluation and
implementation of interactive computing systems for human use and with the study of
major phenomena surrounding them."
GOALS
• A basic goal of HCI is
– to improve the interactions between users and computers
– by making computers more usable and receptive to the user's needs.
• A long term goal of HCI is
– to design systems that minimize the barrier between the human's cognitive
model of what they want
– to accomplish and the computer's understanding of the user's task
WHY IS HCI IMPORTANT
• User-centered design is getting a crucial role!
• It is getting more important today to increase competitiveness via HCI studies (Norman,
1990)
• High-cost e-transformation investments
• Users lose time with badly designed products and services
• Users even give up using bad interface
– Ineffective allocation of resources
2
,DEFINING THE USER INTERFACE
• User interface, design is a subset of a field of study called human-computer interaction
(HCI).
• Human-computer interaction is the study, planning, and design of how people and
computers work together so that
a person's needs are satisfied in the most effective way.
• HCI designers must consider a variety of factors:
– what people want and expect, physical limitations and abilities people possess,
--how information processing systems work,
– what people find enjoyable and attractive.
– Technical characteristics and limitations of the computer hardware and software
must also be considered.
• The user interface is to
– the part of a computer and its software that people can see, hear, touch, talk
to, or otherwise understand or direct.
• The user interface has essentially two components: input and output.
• Input is how a person communicates his / her needs to the computer.
– Some common input components are the keyboard, mouse, trackball,
one's finger, and one's voice.
• Output is how the computer conveys the results of its computations and
requirements to the user.
– Today, the most common computer output mechanism is the display
screen, followed by mechanisms that take advantage of a person's auditory
capabilities: voice and sound.
• The use of the human senses of smell and touch output in interface design still
remain largely unexplored.
• Proper interface design will provide a mix of well-designed input and output
mechanisms that satisfy the user's needs, capabilities, and limitations in the most
effective way possible.
• The best interface is one that it not noticed, one that permits the user to focus on the
information and task at hand, not the mechanisms used to present the information and
perform the task.
3
, THE IMPORTANCE OF GOOD DESIGN
With today's technology and tools, and our motivation to create really effective and usable
interfaces and screens, why do we continue to produce systems that are inefficient and
confusing or, at worst, just plain unusable? Is it because:
• We don't care?
• We don't possess common sense?
• We don't have the time?
• We still don't know what really makes good design?
• But we never seem to have time to find out what makes good design, nor to properly
apply it. After all, many of us have other things to do in addition to designing interfaces
and screens.
• So we take our best shot given the workload and time constraints imposed upon us. The
result, too often, is woefully inadequate.
• Interface and screen design were really a matter of common sense, we developers would
have been producing almost identical screens for representing the real world.
• Example bad designs
– Closed door with complete wood
– suggestion : glass door
THE IMPORTANCE OF THE USER INTERFACE
A well-designed interface and screen is terribly important to our users. It is their
window to view the capabilities of the system.
It is also the vehicle through which many critical tasks are presented. These tasks
often have a direct impact on an organization's relations with its customers, and its
profitability.
A screen's layout and appearance affect a person in a variety of ways. If they are
confusing and inefficient, people will have greater difficulty in doing their jobs and
will make more mistakes.
Poor design may even chase some people away from a system permanently. It can
also lead to aggravation, frustration, and increased stress.
The Benefits of Good Design
Poor clarity forced screen users to spend one extra second per screen.
o Almost one additional year would be required to process all screens.
o Twenty extra seconds in screen usage time adds an additional 14 person
years.
4
