Unformatted text preview: essful (Preece et
al., 1995). The concept of user-centered design has been defined by many researchers in
different ways, for instance, Karat et al., (2003) said that total system functions should
be designed to meet user requirements, user learning and efficient user access; therefore
the ultimate users must see the system as useful and functional.
Eason (1992) grasp a broader view of design and development and figured out four key
stages in development:
4. System planning
System management In support of system planning Eason (1992) stressed that human-computer systems
should be developed in an ordered manner rather than in a temporary way. It is vital to
consider that purpose of the system development and how it will address the other
human and technical systems. Most significantly, it is important to consider how a
system contributes to the overall aims of the business. The system design process and 16 the process of moving from design to implementation involve ensuring that the system
must meet its usability goals. It is critical to manage the change that occurs as a result of
introducing a new system for instance, how the new system implementation will affect
the ultimate user jobs. In order to make the system successful, system has to be
implemented effectively to gain acceptance from ultimate users.
Figure 2.1 Methods for user-centered design (adopted from Eason, 1992)
Preece et al.(1995), Page 372
In the figure above, various techniques and activities are listed around the four circles,
at points which they are relevant. At the right hand side of the figure there are two
methods that cover all those parts of the design that they are positioned adjacent to. 2.2 The objectives of Human Computer Interaction (HCI) design The objectives of HCI (Human Computer Interaction) design are to produce usable,
secure and functional systems. These objectives can be summarized as to develop and
improve the safety, utility, effectiveness, efficiency, and usability of the “Systems” that
include computers. At this point, the term ‘System’ has been derived from system
theory and it deals the whole environment and just not limited to hardware and software
systems. The environment can be a company, a business, people at work or at home or 17 people engaged in leisure activity all use computers or all affected by the computer
technology in somehow.
The term ‘utility’ refers to the functionality of a system or system efforts to improve
‘effectiveness’ and ‘efficiency’ which are clear and fundamental aims. System utility
enables a system to manage and control system operation so that application software
can perform a task successfully.
The term ‘safety’ refers to its relation to computer systems, is a principal importance in
the design of safety critical systems. The system safety concept describes a risk
management strategy based on identification, analysis of possible hazards to system
Therefore, usability is a key concept in HCI concerned with making systems easy to
learn and use. Bottom line, any poor computer system design can be extremely
annoying to end users. (Preece et al.,1995).
Providing a variety of system options or enhanced functionality is not necessarily the
way to ensure system success and good usability. Eason (1992) did a field study of a
banking system that provides the bank staff 36 different ways of extracting information
from a customer’s account. However, after examining the usage logs, he found that just
four codes in use are the 75% of the total usage, and many codes were virtually unused,
even though those were specially designed for banking tasks. The reason, he discovered
that the full flexibility of the system was not explored because users did not put efforts
in learning to use extra search strategies unless they needed it. (Preece et al.,1995).
HCI experts suggests that, in order to produce computer systems with good usability
there are some factors that need to be consider very well, such as psychological,
ergonomic, organizational and social factors that determine how people operate and
make use of computer technology effectively. These factors greatly help in the
development of tools and techniques to help designers to ensure that computer systems
are suitable for the people desired activities. People concern has utmost important in
HCI, since they will use these systems in their every day life. (Preece et al.,1995).
The principal objective of all HCI research and design is the idea that the people (end
user) using a computer system should comes first. User requirements, capabilities and
preferences for performing various tasks should be fulfilled in system development.
“People should not have to change radically to ‘fit in with the system’ the system sh...
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This document was uploaded on 12/31/2013.
- Fall '13
- The Land