"Usability is a quality attribute that assesses how
easy user interfaces are to use. The word "usability"
also refers to methods for improving ease-of-use
during the design process.”
Learnability: How easy is it for users to accomplish basic
tasks the ﬁrst time they encounter the design?
Efﬁciency: Once users have learned the design, how quickly
can they perform tasks?
Memorability: When users return to the design after a period
of not using it, how easily can they reestablish proﬁciency?
Errors: How many errors do users make, how severe are
these errors, and how easily can they recover from the
Satisfaction: How pleasant is it to use the design?
Deﬁnition: Utility = whether it provides the
features you need.
Deﬁnition: Usability = how easy & pleasant
these features are to use.
Deﬁnition: Useful = usability + utility
Maps, info graphics
Houses, Factories, Malls!
Softwares, websites, apps
Why is usability
Satisﬁed users are happier customers
10% of the design budget = 2x sales increase
"User experience" encompasses all aspects of
the end-user's interaction with the company, its
services, and its products.
Information architecture (IA) is the art and
science of organising and labeling data
including: websites, intranets, online
communities, software, books and other
mediums of information, to develop usability and
The 10 most general principles for interaction
design. They are called "heuristics" because they are
more in the nature of rules of thumb than speciﬁc
usability guidelines.We can measure our products
Heuristics for heuristic evaluation developed by
Jacob Nielsen and Rolf Molich in 1990
Nielsen reﬁned it based on a factor analysis of 249
usability problems in 1994
1. Visibility of system
The system should always keep users informed about
what is going on, through appropriate feedback
within reasonable time.
2. Match between system
and the real world
The system should speak the users' language, with
words, phrases and concepts familiar to the user,
rather than system-oriented terms. Follow real-world
conventions, making information appear in a natural
and logical order.
3. User control and freedom
Users often choose system functions by mistake and
will need a clearly marked "emergency exit" to leave
the unwanted state without having to go through an
extended dialogue. Support undo and redo.
4. Consistency and standards
Users should not have to wonder whether different
words, situations, or actions mean the same thing.
Follow platform conventions.
5. Error prevention
Even better than good error messages is a careful
design which prevents a problem from occurring in
the ﬁrst place. Either eliminate error-prone conditions
or check for them and present users with a
conﬁrmation option before they commit to the action.
6. Recognition rather than
Minimise the user's memory load by making objects,
actions, and options visible. The user should not have
to remember information from one part of the
dialogue to another. Instructions for use of the system
should be visible or easily retrievable whenever
7. Flexibility and efficiency
Accelerators -- unseen by the novice user -- may
often speed up the interaction for the expert user
such that the system can cater to both inexperienced
and experienced users. Allow users to tailor frequent
8. Aesthetic and minimalist
Dialogues should not contain information which is
irrelevant or rarely needed. Every extra unit of
information in a dialogue competes with the relevant
units of information and diminishes their relative
9. Help users recognize,
diagnose, and recover from
Error messages should be expressed in plain
language (no codes), precisely indicate the problem,
and constructively suggest a solution
10. Help and documentation
Even though it is better if the system can be used
without documentation, it may be necessary to
provide help and documentation. Any such
information should be easy to search, focused on the
user's task, list concrete steps to be carried out, and
not be too large.
Predicts that the time required to rapidly move to a
target area is a function of the distance to the target
and the size of the target.
The bigger an object and the closer it is to us, the
easier it is to move to.
The time it takes for a person to make a decision as a
result of the possible choices he or she hasThe
bigger an object and the closer it is to us, the easier it
is to move to.
The more options, the more difﬁcult to choose
Elements with similar functions should be grouped
physically and visually.
Use the logo as a link for navigating to the main
The user should always know where is he on the
Links should be visually different and they should
speak for themselves
The text should be always readable
Try to highlight important informations for quicker
The structural design of shared information
The art and science of organizing and labeling web
sites, intranets, online communities, and software to
support ﬁndability and usability.
The combination of organization, labeling, search and
navigation systems within websites and intranets.
narrow and deep
broad and shallow
web or tag-based
Never stop asking questions
Measuring analytics can answer the what?
Usability research can answer for the why?
Combine analytical data with the UX research for
Usability research types
A/B or multivariate tests
You can test on…
Existing website or app
Wireframes or graphics
Use real life tasks (Book a ticket, Find someone)
Ask the participants to think loudly (“I think I should
click here to …”)
Start the test from a realistic environment (Google)
Some misbeliefs about
People can tell you what they want
User research is expensive
People are rational
They click on the red buttons more often
You know what your users wants
You can get answers for these
question by measuring you
Where are they coming from?
What are they doing on my website?
When and where are they leaving it?
You can get answers for these
question by measuring you
Content: What should be on the main page?
Structure: What kind of content should go into the
main menu point?
Do we need detailed search options?
Should we optimise our website for mobiles?
Analytics can tell you what are your users, visitors
are doing but it cannot tell you why are they doing
Integrate in multiple marketing channels