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the complexity of user interfaces. Lately, it has
been observed that users are unwilling to put up
with uncomfortable or difficult since experience
with some current interfaces has shown them that
software can indeed be easy to learn and pleasant
to use (Nielsen, 1994). Therefore, high usability
is a must requirement of a software application,
since there are an increasing number of mature
and competing products in the market. However,
without proper usability evaluation methods,
it's not possible to measure the usability level
of a particular application as all contemporary
commercial products where product maturity
and technical challenges are already left behind
within/among competing products.
There are many usability evaluation meth-
ods for different domains, from mobile devices
(Kjeldskov and Stage, 2004) to interactive TV
sets (Pemberton and Griffiths, 2003; Daly-Jones,
2002; Gauntlett and Hill, 1999). These include
expert evaluations like cognitive walkthroughs
(Lewis, Polson, Wharton and Rieman, 1990;
Wharton, Bradford, Jeffries and Franzke, 1992) or
heuristic evaluations (Nielsen and Molich, 1990).
We can classify usability evaluation methods into
four, namely formal methods, automated meth-
ods, empirical methods and heuristics. A formal
method (Card, Moran & Newell, 2003) benefits
from formal and metric models to take usability
measurements. Automatic method measures us-
ability by measuring a user specification through
an application. It stems from usability measures to
describe the functioning of a system through the
assessment of the software (Byrne et. al., 1994).
An empirical method provides the most reliable
methodology among all, since it incorporates
a sample of real world users by examining the
properties of usability and observing how a size-
able sample of real users uses the system (Butler,
1996). The inspection method is based on the
heuristics and rules of functioning, and it includes
a single assessor who carries out the inspection of
the application (Nielsen, 1990). Other sub-types
of evaluation methods include verbal protocols
(Ericsson and Simon, 1984), critical incident re-
porting (del Galdo, Williges, Williges and Wixon,
1987) and user satisfaction ratings (Chin, Diehl
and Norman, 1988).
Usability processes produce competing prod-
ucts, by consistently evaluating the user interface
using methods mentioned above. Obviously,
coordinated and cooperative design has been an
important task lately, with the introduction of
Internet and internet-enabled software houses.
In an open source world, there's a lack of under-
standing of “representative user”, who will help
assess the end product usability. Without this pool
of users, developers can only imagine and develop
according to their mental model, potentially ignor-
ing end user tasks. According to Nielsen (1994),
users should be involved in the design process
through regular meetings between designers and
users however this is often not possible when the
software is developed internationally, speaking
of thousands of kilometers between developers'
country borders. Current attempts to gather de-
velopers and usability experts in regular meetings
do not disperse the issue of “lack of interaction”
with end users.
User contribution to product usability has been
investigated in the literature for a long time. They
are not designers, however can propose different
interaction alternatives like designers when they
are given enough time, support and environment.
On the other hand, since reactions and critics to
design could act as a barrier towards new incen-
tives and building blocks for innovation. A com-
munication channel is required, exploiting the
advantages of the Internet, by guiding users to a
productive discussion. In an internet-supported
environment where software is developed in a free
and unrestricted manner, a centralized, decision
making authority is needed to focus the discussions
not only for development, but also for usability
merits. Both usability experts and end users expect
to be encouraged to design smaller instances of
a big picture so that these parts are regarded as
design representatives or instances of illustration.
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