Prototyping

Prototyping

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...

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