DISCIPLINE OF HUMAN COMPUTER INTERACTION

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Human Computer Interaction (CS408)

Lecture

Lecture 5. Discipline of Human Computer

Interaction

Learning Goals

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:

Describe the relationship of Usability and quality

Understand HCI Discipline

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: what can the technology do?

How can you build it? What are the possibilities? And one eye open to the question:

what are people doing and how would this fit in? 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 I think 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?'

5.1 Quality

Let us firstly look at a general definition of quality.

According to the American Heritage Dictionary "characteristic or attribute of

something." As an attribute of an item, quality refers to measurable characteristics---

things we are able to compare to know standards such as length, color, electrical

properties, malleability, and so on.

Now as we are concerned with software quality so let us look at some other

definitions:

According to British Defense Industries Quality Assurance Panel "Quality is

conformance to specifications". So, according to this definition quality is the measure

of degree to which the design specifications are followed during manufacturing. The

greater the degree of conformance, the higher the level of quality is.

Philip Crosby describes, "Quality is conformance to requirements." Here software

requirements are the foundation from which quality is measured. Lack of

conformance to requirements is lack of quality.

Juran

says,

"Quality

fitness

for

purpose

use"

"Quality is a predictable degree of uniformity and dependability, at low cost and

suited to the market", defined by Edward Deming.

Human Computer Interaction (CS408)

By R J Mortiboys "Quality is synonymous with customer needs and expectations."

"Quality is meeting the (stated) requirements of the customer- now and in the future."

By Mike Robinson.

"Quality is the total composite product and service characteristics of marketing,

engineering, manufacturing and maintenance through which the product and service

in use will meet the expectations by the customer"

(Armand Feigenbaum)

"Totality of characteristics of an entity that bear on its ability to satisfy stated and

implied needs."

ISO 8402 : 1994)

All above-mentioned definitions refer quality as a conformance to requirements or

conformance to specification or as a synonymous with customer needs and

expectations etc. In my point of view or with respect to HCI, quality is something

beyond meeting the specifications, requirements or customer expectations. For

example, consider a scenario, as you know, there is always a quality assurance

department in any software house which checks the final products with reference to

their specification or requirements. The products that do not fulfill their specifications

or requirements they are considered bugged. In my scenario, what will be the matter if

the specifications or requirements, which are being used to measure quality, are not

complete? That's why, I think, quality is beyond the conformance to specifications or

requirements or even the customer expectations.

I think quality cannot be measured just by the requirements or specifications

described by the customer rather you should approach to that end user who will use

this product. The expectations or needs of the end user can be the measure of quality.

So, we can say, as much as the product will be useable for end user as much higher

will be its quality.

To understand the relationship of quality and usability in a software reference, look at

the definition of software quality. "The extent to which a software product exhibits

these characteristics"

Functionality

Reliability

Usability

Efficiency

Maintainability

Portability

5.2 Interdisciplinary nature of HCI

Human Computer Interaction (CS408)

Organizational Factors

Environmental Factors

Training, job design, politics, roles Work organization

Noise, heating, ventilation,lighting

Cognitive processes and capabilities

Health and Safety

Comfort Level

The User

Stress, headaches,

Seating Equipment layout

Muscular-skeleton,

Motivation, Enjoyment, Satisfaction, Personality

disorders

Experience level

User Interface

Input devices, output displays, dialogue structures, User of colour, icons, commands, graphics, natural

language

Task Factors

Easy, complex, novel, Task allocation, repetitive, Monitoring, skills, multi-media

Constraints

System Functionality

Hardware, software, application

Productivity Factors

Increase output, increase quality, decrease costs, decrease errors, decrease labour requirements, and decrease

production time, Increase creative and innovative ideas leading to new products

The main factors that should be taken in account in HCI design are shown in above

figure. Primarily, these relate directly to users, such as comfort and health, or are

concerned with users' work, the work environment or the technology being used.

What makes the analysis even more complex is that many factors inevitably interact

with each other. For example, if changes are made to improve productivity, this may

have undesirable effects on users' motivations and levels of satisfaction because

issues relating to job design and work organization are ignored.

Case Study Ticketing System

A small travel agency with a number of shops distributed throughout the country

decides that, in order to survive in the travel industry, it needs to install an efficient

ticketing system. Current practice involves sales staff in a lengthy procedure for

issuing tickets to customers. First they have to call an airline to check if there are any

vacant seats for the time when the customer wishes to fly. Then they have to check

with the customer which of the available seats is suitable before making a reservation

with the airline. The ticket is then written out by hand. In addition, the customer needs

a receipt and an itinerary, which are also written by hand. One of the biggest problems

with this practice is getting a telephone connection to the airline. This means that

customers often have to wait while a frustrated sales assistant keeps trying in vain. To

overcome this problem it is common practice to ask the customers to come back later

in the hope that the sales staff will manage to get through to the airline in the

meantime. Another time-consuming job is accounting for each ticket that has been

issued, and the sales staff has to do this by hand every two weeks.

Human Computer Interaction (CS408)

Before deciding to get new system the branch manager does some background

research into how the agency really functions. She starts by visiting branches in a

sister company that is using a computerized ticketing system. After talking to the staff

for just a short time she discovers that there are problems. The sales staff complains

that the computer is always going wrong and that they don't trust it. Furthermore, they

can't understand some of the messages that it produces when they make errors. In

fact, they wish they could go back to the old un-computerized way of working. Sales

figures since the new system was installed are also disappointing and a large number

of staff have left the office. Not surprisingly, the manager is consultants examine the

users' needs and how they currently go about their work in detail and also find out

exactly what the goals of the company are. They then recommend a system with the

following characteristics:

· Immediate ticket booking via a computer connection (alleviating the problem

of engaged phone line),

· Automatic print-out of tickets, itineraries and receipts (eliminating the need to

write these by hand and thereby reducing the possibility of errors and

illegibility while speeding up the process),

· Direct connection between the booking system and accounting (speeding up

the process of accounting),

· Elimination of booking forms (reducing overheads as less paper and time are

used).

The consultants suggest making the interface to the system mimic the non-

computerized task, so menus and forms are used, which means that the sales assistant

only has to select options and fill in the resulting forms by typing at a keyboard.

The consultants are optimistic that customer satisfaction will improve because

customer will get their tickets on the spot. They point out to the manager, however,

that in order to get the most out of the new system the layout of the agency needs to

be changed to make it comfortable for the sales staff to operate the compute, while

still providing scope for direct contact with customers. Staff will also need training,

and some careful changes to existing jobs are needed too--job design. In particular,

technology means that they will need support during the period of change. Staff will

also need to know how to cope when an airline's computer malfunctions. Changes in

employment conditions must also be examined. For instance, if staff is expected to

carry out more transactions in less time, are they going to be rewarded for this extra

activity? Staff relations with other staff in the company who will not be using the

computerized system must also be taken into account. For example, problems

associated with technology power such as feelings f elitism among staff that know

how to use the new technology, will need to be resolved.

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.

Human

Cognitive Psychology

Human Computer Interaction (CS408)

Social Organizational Psychology

Ergonomics and Human Factors

Linguistics

Philosophy

Sociology

Anthropology

Machine

Computer Science

Artificial Intelligence

Other

Engineering

Design

Cognitive Psychology

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 notion of information processing. Everything we see, feel,

touch, taste, smell and do is couched in terms of information processing. The

objective cognitive psychology has been to characterize these processes in terms of

their capabilities and limitations. [2]

Social and Organizational psychology

Social psychology is concerned with studying the nature and causes of human

behavior in a social context. Vaske and Grantham identify the four core concerns of

social psychology as:

· The influence of one individual on another person's attitudes and behavior

· The impact of a group on its members' attitude and behavior

· The impact of a member on a group's activities and structure

· The relationship between the structure and activities of different groups.

The role of social and organizational psychology is to inform designers about social

and organizational structures and about how the introduction of computers will

influence working practices. [2]

Ergonomics or human factor

Ergonomics, or human factor, developed from the interests of a number of different

disciplines primarily during World War II. Its purpose is to define and design tools

and various artifacts for different work, leisure and domestic environments to suit the

capabilities and capacities of users.

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

Human Computer Interaction (CS408)

maximize an operator's safety, efficiency and reliability of performance, to make a

task easier, and to increase feelings of comfort and satisfaction. [2]

Linguistics

Linguistics is the scientific study of language (Lyons, 1970). From the point of view

of HCI there are several issues that may be better understood by applying knowledge

and theories from linguistics. For example, in the early days of command languages

there was some debate about whether or not the object to which a command applied

should come before or after the command itself. When deleting a file called `xyz', for

example, should you type delete `xyz' or `xyz' delete. [2]

Philosophy, Sociology and Anthropology

A major concern of these disciplines until relatively recently has been to consider the

implication of the introduction of IT to society. More recently, attempts are being

made to apply methods developed in the social sciences to the design and evaluation

of systems. The reason for applying social science methods of analysis to HCI, it is

argued, are that a more accurate description of the interaction between users, their

work, the technology that they use and the environment in which they are situated can

be obtained. One application of social science methods has been to characterize

computer supported cooperative writing (CSCW), which is concerned with sharing

software and hardware among groups of people working together. The is to design

tools and ways of working which optimize the shared technology so that maximum

benefit can be obtained by all those who use or are affected by it. [2]

Artificial Intelligence

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. These include, for example, the use of natural language and

speech as a way of communicating with a system and the need for system to explain

and justify its advice. [2]

Computer Science

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. In particular, there has been a strong interest in automating design and

development when feasible. [2]

Engineering and design

Engineering is an applied science, which relies heavily on model building and

empirical testing. 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.

Human Computer Interaction (CS408)

Design too is a well-established discipline in its own right, which has potential

benefits when applied to HCI problems. An obvious example is graphic design.[2]

Reference:

Human-Computer Interaction by Jenny Preece

Software Engineering A Practitioner's Approach by Roger S. Pressman

Definitions of Quality - Sandeep's Quality Page.htm

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