Usability
User-Based Practices
• Questions
• Organization
• Sign Posting
• Background
Anderson, Chapter 4
https://www.krispykreme.com/
Usability is…
• Useful: Your content should be
original and fulfill a need
• Usable: Site must be easy to use
• Desirable: Image, identity, brand,
and other design elements are used
to evoke emotion and appreciation
• Findable: Content needs to be
navigable and locatable onsite and
offsite
• Accessible: Content needs to be
accessible to people with disabilities
• Credible: Users must trust and
believe what you tell them
When to Work on Usability
Usability plays a role in each stage of the design process. The resulting need for multiple studies is
one reason I recommend making individual studies fast and cheap. Here are the main steps:
•
Before 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.
•
Unless you're working on an intranet, test your competitors' designs to get cheap data on a
range of alternative interfaces that have similar features to your own. (If you work on an
intranet, read the intranet design annual to learn from other designs.)
•
Conduct a field study to see how users behave in their natural habitat.
•
Make 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.
•
Refine the design ideas that test best through multiple iterations, gradually moving from lowfidelity prototyping to high-fidelity representations that run on the computer. Test each
iteration.
•
Inspect the design relative to established usability guidelines whether from your own earlier
studies or published research.
•
Once you decide on and implement the final design, test it again. Subtle usability problems
always creep in during implementation.
“Usability refers to the quality of a user’s
experience when interacting with products or
systems, including websites, software, devices, or
applications”
• Intuitive design: a nearly effortless understanding of the
architecture and navigation of the site
• Ease of learning: how fast a user who has never seen the user
interface before can accomplish basic tasks
• Efficiency of use: How fast an experienced user can accomplish
tasks
• Memorability: after visiting the site, if a user can remember
enough to use it effectively in future visits
• Error frequency and severity: how often users make errors while
using the system, how serious the errors are, and how users
recover from the errors
• Subjective satisfaction: If the user likes using the system
Usability Testing
• Planning
• Conducting
• Interpreting
• Define your goals
• Choose Testers
• Use the draft/deliverable as your target readers would
• Tasks, Location, Resources, Information Gathering
• Post Task Interview
Test for Persuasiveness
• Likert-scale questions
• Avoid Bias
• Treatment of Test Readers
Test’s purpose
Think they will do during the test
Time required
Where the test will occur
Risks
Right to Decline
Right to stop at anytime
Determine which type of usability test to implement
Depending on where you are in the design process, there are three types of usability
tests to choose from. These are the exploratory, assessment, and validation tests. A fourth
type, the comparison test, can be used at any point in the design life cycle.
Exploratory Test: The objective is to explore the user's mental model of the task you're
trying to facilitate.
• When to use: This type of test is usually conducted during the initial phases of a
design life-cycle. This test is effective when the designers are still grappling with what
functionality to include in the final product.
• Objective: Evaluates whether the user can distinguish between the functional elements
of an interface; whether the user values the functions presented; whether the overall
structure enables a "walk up and use" product. The test seeks to establish the
intuitiveness of the implementation.
• Methodology: This test involves a high degree of interaction between the monitor and
the subject. The purpose of the test is to identify points of confusion encountered by
the user and then to "walk through" what would help them out.
• Test Example: The user is shown an example of a mundane situation, i.e. a screen
shot of a user-account management tool, and then asked to talk through their
assumptions, expectations, wishes, etc.
Assessment Test: This is the most common test conducted.
• When to use: Normally conducted early or midway through
the design of the product.
• Objective: This test assumes that the basic conceptual models
are decided and determines how well they've been
implemented. The test seeks to measure the effectiveness of
the implementation.
• Methodology: The user performs tasks while the monitor
largely stays out of the way. Quantitative measurements are
gathered.
• Test Example: User is asked to accomplish a book renewal.
Validation Test:
• When to use: This test normally takes place close to the release of
the product.
• Objective: The purpose of this test is to establish that the product
performance meets or exceeds benchmark standards in time and
effort required to accomplish a task. These standards are arrived
at either through previous tests or educated guesses. This test also
measures how well all the pieces of the design work together.
• Methodology: Benchmarks are first established for the tasks. The
tasks are then given to users and the resulting completion efforts
monitored. The resulting quantitative data is analyzed and
timings over benchmark are identified as possible problem areas.
• Test Example: "Access your library account, identify if any books
are due soon and then renew them if they are. Benchmark = 1
minute”
Comparison Test: This test compares the users reactions to
multiple examples of a tool or implementation.
• When to use: This test can be used at any stage in the design
process to compare radically different designs or
implementations against each other.
• Objective: This test is used to determine which design is easiest
to use and what are the advantages and disadvantages between
designs.
• Methodology: This test can be an exploratory test where
multiple designs are compared qualitatively. The usual result is
an improved product which combines the best of many
different ideas. The best results normally come from
comparing examples of wildly differing implementations.
• Test Example: "Locate a tutorial on finding scholarly journals
on the following library websites."
• Rubin, p. 30-42
Types of Usability Testing
• Hallway Testing
• Remote Usability Testing
• Expert Review
• Paper Prototype Testing
• Questionnaires and Reviews
• Do-It-Yourself Walk Through
• Controlled Experiments
• Automated Usability Testing
http://usabilitygeek.com/an-introduction-to-website-usabilitytesting/
Other Testing
• Focus Group
• Tree Testing
• Beta Testing
• User Diaries
http://blog.usabilla.com/the-top-5-user-testing-methodsof-ux-professionals/
Role of Test Monitor
• Be a good listener
• Build a rapport with the participant
• Be flexible and open to changes in the usability plan
• Maintain a long attention span
• Try not to lead the participant--they need to find the answer themselves!
• Try not to act too knowledgeable--playing dumb can raise some
interesting results.
• Try not to jump to conclusions--strive to pick out patterns while not
allowing that knowledge to color your interaction with the participant.
http://www.lib.washington.edu/usability/resources/guides/tests#section-2
Rubin, p. 64-72