You can see how the concept can be readily applied to web site design – web visitors
often have defined goalssuch as finding particular information or completing an action
such as booking a flight or viewing an account balance.
In Jakob Nielsen’s classic book Designing Web Usability(Nielsen, 2000b), he describes
usability as follows.An engineering approach to website design to ensure the user interface of the site is
learnable, memorable, error free, efficient and gives user satisfaction. It incorporates test-
ing and evaluation to ensure the best use of navigation and links to access information in
the shortest possible time. A companion process to information architecture.
In practice, usability involves two key project activities. Expert reviewsare often per-
formed at the beginning of a redesign project as a way of identifying problems with a
previous design. Usability testinginvolves:
1 Identifying representative users of the site (see, for example, Table 7.3) and identify-
ing typical tasks;
2 Asking them to perform specific tasks such as finding a product or completing an order;
3 Observing what they do and how they succeed.
For a site to be successful, the user tasks or actions need to be completed:
Effectively – web usability specialists measure task completion, for example, only 3
out of 10 visitors to a web site may be able to find a telephone number or other piece
of information.
Efficiently – web usability specialists also measure how long it takes to complete a task
on-site, or the number of clicks it takes.
Jakob Nielsen explains the imperative for usability best in his ‘Usability 101’
(www.useit.com/alertbox/20030825.html). He says:
On the Web, usability is a necessary condition for survival. If a website is difficult to use,
people leave. If the homepagefails to clearly state what a company offers and what users can
do on the site, people leave. If users get lost on a website, they leave. If a website’s informa-
tion is hard to read or doesn’t answer users’ key questions, they leave. Note a pattern here?
For these reasons, Nielsen suggests that around 10% of a design project budget should be
spent on usability, but often actual spend is significantly less.
Some would also extend usability to include testing of the visual or brand design of a
site in focus groups, to assess how consumers perceive it reflects the brand. Often, alter-
native visual designs are developed to identify those which are most appropriate.RESEARCHING SITE USERS’ REQUIREMENTSExpert reviews
An analysis of an
existing site or
prototype, by an
experienced usability
expert who will identify
deficiencies and
improvements to a site
based on their
knowledge of web
design principles and
best practice.
Usability/user
testing
Representative users
are observed
performing
representative tasks
using a system.Table 7.3 Different potential audiences for a web siteCustomers vary by Staff Third parties
New or existing prospects
Size of prospect companies
(e.g. small, medium or large)
Market type (e.g. different
vertical markets)
Location (by country)
Members of buying process
(decision makers, influencers, buyers)
Familiarity (with using the web, the
company, its products and services or
its web site)New or existing
Different departments
Sales staff for different markets
Location (by country)New or existing
Suppliers
Distributors
Investors
Media
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