Paper Prototyping
and
Heuristic Evaluation
Krzysztof Gajos
CS 179, Spring 2010
with materials from James Landay, Andy Ko, and Scott Klemmer
Hall of Fame?
Hall of Shame?
Genres of assessment
Automated
Usability measures computed by
software
Empirical
Usability assesses by testing with
real users
Formal
Models and formulas to calculate
measures
Inspection
Based on heuristics, skills, and
experience of evaluators
Paper Prototyping
Paper Prototyping
•
Before: write the tasks (what the user is to accomplish
but not how)
•
When they come:
•
Describe the purpose, tell them to think aloud, tell
them you won’t provide help or instructions
on the task
•
•
•
Describe the task
Watch them “perform” the task
Take notes!!!
Genres of assessment
Automated
Usability measures computed by
software
Empirical
Usability assesses by testing with
real users
Formal
Models and formulas to calculate
measures
Inspection
Based on heuristics, skills, and
experience of evaluators
Heuristic Evaluation
Developed by Jakob Nielsen
Helps find usability problems in a UI design
Small set (3-5) of evaluators examine UI
independently check for compliance with usability principles
(“heuristics”)
different evaluators will find different problems
evaluators only communicate afterwards
findings are then aggregated
Can perform on working UI or on sketches
Visibility of System
Status
In most cars,
position of the
shifter shows what
gear the car is in
In Prius, the shifter
snaps back to
center; one has to
look at the
instrument panel
on the dashboard
to see the current
mode
Match Between System
and the Real World
• Decades later, one
still has to “trash”
a disk to eject it
User Control and
Freedom
Wizards constrain the order in which choices can
be made; changing a selection requires potentially
multiple navigation...