Transcript Web Usability - Programmiamo

Web Usability
What is usability
Usability is the measure of the quality of a
user's experience when interacting with a
product or system — whether a Web site, a
software application, mobile technology, or
any user-operated device.
In details
Usability is a combination of factors that
affect the user's experience with the
product or system, including:
– Ease of learning
– Efficiency of use
– Memorability
– Error frequency and severity
– Subjective satisfaction
Ease of learning
How fast can a user who
has never seen the user
interface before learn it
sufficiently well to
accomplish basic tasks?
Efficiency of use
Once an
experienced user
has learned to
use the system,
how fast can he
or she
accomplish
tasks?
Memorability
If a user has used the
system before, can he or
she remember enough
to use it effectively the
next time or does the
user have to start over
again learning
everything?
Error frequency and severity
How often do users
make errors while
using the system,
how serious are
these errors, and
how do users
recover from these
errors?
Subjective satisfaction
How much does the
user like using the
system?
Some examples of bad design
Web usability 1
“On the Web, usability is a
necessary condition for
survival. 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. Note
a pattern here?”
Jakob Nielsen
Web usability 2
– Define the purpose of the Web site
– Identify target users
– Get to know your users
– Define the users’ tasks
– Determine scope, usage and change
characteristics of the information
– Define the “personality” of your site
Typical Web user behaviors which have design implications:
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Users do not always start at your home page.
Users may be interested in only a small part of your site.
Users scan before deciding whether to read the entire page.
Users find it harder to read text on-line.
Users care about their time.
Users don’t want to spend unnecessary effort.
Users do get lost.
Users do appreciate pages that are pleasing.
Users do not have the same platform or the same browser.
Some users have text-based browsers.
Web Site Usability Checklist
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Design a clear and simple navigation system
Keep the content clear and simple
Support your brand
Keep colors and page layout consistent
Provide for visitor feedback
Test the site on real users
A simple navigation system
According to Web usability expert, Jakob Nielsen,
a good navigation system should answer three
questions:
•Where am I?
•Where have I been?
•Where can I go?
Keep the content clear and simple 1
You may attract
visitors with an eyecatching design,
but content is what
keeps them at the
site and
encourages them
to return.
Content is also the
best way to boost
your site in search
engine rankings.
Keep the content clear and simple 2
• Make page content easy to scan
• Avoid using text inside images whenever
possible
• Add ALT and TITLE attributes to all images
• Contrast, contrast, contrast!
Support your brand
A good brand creates or reinforces a user's
impression of the site. When your site is
strongly branded, that means that visitors
will think of you first when they go shopping
for your product or service.
Keep colors and page layout consistent
Visitors should
never click on an
internal link in
your site and
wonder if they've
left your web site.
Choose your
colors and fonts
carefully and use
them consistently
throughout the
site.
Provide for visitor feedback
Forms are critical to
the success of
ecommerce sites.
But any site usually
needs at least one
form to allow for
user feedback.
Test the site on real users
Usability testing
helps you
replicate the
experience of
the average
Web site user
and correct
problems before
online visitors
find them.
Some bad examples of web design 1
Some bad examples of web design 2
Some bad examples of web design 3
Some bad examples of web design 4
And a good one…