Civil Engineering Reference
In-Depth Information
Google have been so successful is because of their simplicity in design (
The Economist,
2004). Google has a 27-word interface and iPod has one rotary control.
Consumer
Reports
now devotes about 40% of its reviews to the usability and usefulness of a
product.
Just as in product design, prototypes are very helpful in software development. The
purpose of these is to gather information on usability, which can then be used as a basis
for improvements and redesign.
During the initial phase paper prototypes can be used. Although a paper prototype may
not be appropriate for user testing, usability experts can use it for a cognitive
walkthrough, as explained below. During the later development phases software
prototypes can be evaluated in user testing. The results can be expected to improve
functionality as well as usability.
According to Karat (1997) there are significant economic benefits in improving
usability. Usability is critical to product design. Products with poor usability will not sell;
it may already be too late to improve usability, since the costs for postrelease changes are
not affordable for most companies. An early introduction is critical, so there is rarely a
second chance. The loss of momentum and customer goodwill may even make it difficult
to continue in the same market area.
Usability Engineering contributes to various stages of the product design cycle and
benefits accrue throughout the product life cycle. But it is less expensive to implement
usability in the beginning of the design effort. Gould (1997) proposed a checklist to
ensure early usability testing of software (see Table 7.3).
TABLE 7.3
Checklist for Achieving Early User
Testing
We have made informal, preliminary sketches of a few user scenarios—specifying exactly what the
user and system messages will be—and showed them to a few prospective users.
We have begun writing the user manual, and it is guiding the development process.
We have used simulations to try out the functions and organization of the user interface.
We have used mockups.
We have invited people to comment on usability components.
We had prospective users think aloud as they used simulations and prototypes.
We used hallway and storefront methods.
We did formal prototype user testing.
We met our behavioral benchmarking.
We did field studies.
We did follow-up studies on people who use the system.
Adapted from Gould (1998).
7.4
USABILITY
It is essential to emphasize usability in software development. Indeed, usability has
become so important that a new profession has been established: usability experts and
usability engineers. Many belong to the Usability Professionals Association (UPA), a
body of professionals who take a pragmatic view of their work by focusing on design
