Usability Testing
Introduction
“Usability” denotes certain factor's about the user's experience with a
product or a system.The key factors which suits to the usability are:
Ease of learning:-This factor describes how fast it takes an user to learn the system inorder to achieve basic tasks.
Efficiency
of use:-This factor describes how much time will the product/system
takes to perform the task once the user undergoes with the product.
Memorability:-This factor determines how easily the user remember's the use when he approaches the next time.
Error
frequency and severity:-This determines how frequent are errors in the
system,how severe the errors are and how do users recover from errors.
Subjective
Satisfaction:-This factors determines about how the user react to the
system/product and what the user feels about it .
What is Usability Testing ?
“Usability testing” defines the measure of the quality of a user's
experience when interacting with a system i.e a website,software
application,mobile technology,or any user operated device.Basically
usability testing is performed to determine user interface design
problems which is done in two levels:
On a conceptual level-which relates to navigation,user orientation and UI constitency
On
a detailed design level-which refers to GUI standards and
guidelines,terminology used,specific problems.Once the problems are
found they are prioritized by severity and are suggested for redesign.
During testing,users are observed interacting with an application.The
test setup is designed to be as faithful as possible to all conditions
and user types targeted by the product.Tests are usually videotaped.The
sessions are observed and the tapes subsequently studied to discover
trends and to extract performance data.Elements of the interface that
are effective across the test population can be considered validated as
well designed solutions.Elements that consistently fail are
identified,analyzed and redesigned to improve user interface
effectiveness.
Importance of Usability testing
Generally product quality problems undertakes two major forms-one is
the programming bugs and other is the design flaws.If these problems
are exposed late in the product life cycle then the costs associated
might increase exponentially.So accurate knowledge of the usability of
a given user interface reduces risk in later stages of development.
Apart from reducing risk it also maximizes ROI(Return On Investment) by
injecting realistic and accurate measures into the design and
development process.
It is basically carried out at various
stages of the design process. In the early stages of development,
clients especially value wizard test as it allows quick estimation of a
proposed design.In mid-stage testing of prototypes, results with higher
fidelity measures thereby influencing the design while it is still
flexible and responsive to change.Late-stage testing through validation
and acceptance methods-provide exposure of flaws that are otherwise
reported, at great expense,by the customers themselves.
Methods of Usability Testing
Laboratory
experiments:In this method of testing, users are introduced to the
system and are required to perform several key tasks according to
preset scenarios.The test may be performed on a real project, or on a
demo that specifies the system that are to be tested. User activities
are recorded using two cameras one that records on-screen activities
and the second that records the user response and expressions.
On-site
observation:This test is conducted onsite.It is usually done when the
system or environment are too complicated to be replicated in the
laboratory.This tests helps to study users in their real
environment.The advantage of this type of testing gives the users a
less formal feeling regarding the test and enables a relatively long
observation period.It also helps to collect information from a real
environment rather than from preset scenarios.
Questionnaires:This
test method reveals about the detailed feedback from the users about
the use of the system. This gives a good indication regarding the
user's experience of using the system.In this case an online
questionnaire or paper form may be used.The advantage of questionnaire
is that the feedback is based on the user's subjective experience with
the system, its perceived usefulness and usability.
Heuristic
Evaluation:A systematic evaluation of the user interface generally
performed by more than one usability expert according to known
standards(heuristics).This test discovers the critical problems at a
relatively early stage.This test is best performed before closing a
version and before any other type of usability testing.
Key Area's of Testing Usability:
Graphical
User Interface(GUI):This is the front end or part of the software
application or website that the user see and work with.
Navigation:This
determines how the user gets from one place in an application or
website to another.This includes the menu structure-one,two or more
levels,drop down navigation,hyperlinks etc.
Orientation:This
determines how the user knows his location within the application or
website.The user's orientation is critical for future navigation and
for a feeling of “understanding the application” and easily correcting
navigation mistakes.
Constituency:This determines the action's
that cause the same reactions in similar situations. For e.g clicking
on a hyperlink opens a pop-up window whereas clicking on button takes
you to a new screen.
Conclusion
Usability testing
not only evaluate the use of the product but also improve the process
of iterative design as designers are provided with critical usability
information that can guide the design during the process and thus
demonstrate the predictive validity of the service, rather than at the
end of the design phase.
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