THE Complete Web Usability Site - See Jakob Nielsen's:
basic and useful is method for studying usability is
user testing, which has three components:
the users to perform representative tasks with
what the users do, where they succeed, and where
they have difficulties with the user interface. Shut
up and let the users do the talking.
Usability has five components:
How easy is it for users to accomplish basic tasks
the first time they encounter the design?
Once users have learned the design, how quickly
can they perform tasks?
When users return to the design after a period
of not using it, how easily can they reestablish proficiency?
How many errors do users make, how severe are these
errors, and how easily can they recover from the errors?
How pleasant is it to use the design?
A key attribute is utility, which refers to the design's functionality:
Does it do what users need? Usability and utility are equally
important: It matters little that something is easy if it's
not what you want. On the Web, usability is a necessary condition
- If a website
is difficult to use, people leave.
- If the
homepage fails 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
information is hard to read or doesn't answer users'
key questions, they leave.
are plenty of other websites available; leaving is
the first line of defense when users encounter a difficulty.
plays a role in each stage of the design process.
starting the new design, test the old design to
identify the good parts that you should keep or emphasize,
and the bad parts that give users trouble.
competitors' designs to get cheap data on a range
of alternative interfaces that have similar features
to your own.
a field study to see how users behave in their
paper prototypes of one or more new design ideas
and test them. The less time you invest in these design
ideas the better, because you'll need to change them
all based on the test results.
the design ideas that test best through multiple
iterations, gradually moving from low-fidelity prototyping
to high-fidelity representations that run on the computer.
Test each iteration.
the design relative to established usability guidelines,
whether from our own earlier studies or published research.
we decide on and implement the final design, test
it again. Subtle usability problems always creep in
The only way to a high-quality user experience is to start
user testing early in the design process and to keep testing
every step of the way.