Transcript Chapter X: Put chapter title here

Introducing Evaluation:
why, what, when, where
Text p 317 – 323; Text p 586- 595
Bruce Tognazzini tells you
why you need to evaluate
“Iterative design, with its repeating cycle of
design and testing, is the only validated
methodology in existence that will consistently
produce successful results. If you don’t have
user-testing as an integral part of your design
process you are going to throw buckets of
money down the drain.”
See AskTog.com for topical discussions about
design and evaluation.
Why, what, where & when
Iterative design & evaluation is
that examines:
•
• Why: to check that
users can use the
product and that
they like it.
• What:
– a conceptual
model,
– early prototypes
of a new system
and later,
– more complete
prototypes.
a continuous process
Where:
– in natural and
– laboratory
settings.
• When:
– throughout
design;
– finished products
can be evaluated
to collect
information to
inform new
products.
Why evaluate?
• Designers get feedback about their eraly
design ideas
• Major problems are fixed b fore the
product goes on sale
• Designers focus on real problems rather
than debating what each other likes or
dislikes about the product
Why evaluate
• You will never second-guess how people
use your designs
• We all get emotionally attached to our
designs and need perspective
Yes, your baby may be ugly
What to evaluate?
•
•
•
•
Usability
Emotional qualities
Engaging qualities
Motivating qualities
Where to evaluate
• Depending what you are evaluating will
determine location
• Examples
– how different users use a mobile
phone will require a naturalistic
setting
– Sequence of links on a website can be
done in a controlled lab setting
When to evaluate
Throughout design
• From the first descriptions, sketches etc.
of users needs through to the final
product
• Design proceeds through iterative cycles
of ‘design-test-redesign’
• Evaluation is a key ingredient for a
successful design.
When to evaluate
• Depends on the product
• Summative evaluation occurs to assess the
success of a FINISHED product
• Formative evaluation is done ruing the design
process to check that the product continues to
meet users needs
• Formative evaluation cover abroad span of the
design from early development sketches etc, to
tweaking an almost finished design
The language of evaluation
Evaluation has a set of terms with which you will need to
become familiar. Use your text to find the definitions of the
main ones listed here
• Analytical evaluation
• Controlled
experiment
• Field study
• Formative evaluation
• Heuristic evaluation
• Predictive evaluation
• Summative
evaluation
• Usability laboratory
• User studies
• Usability studies
• Usability testing
• User testing