Transcript CSIS-114 Lab #10

CSIS-114
Lab #4
Part Two
Elements of Designing the User Interface
“Designing an object to be simple
and clear takes at least twice as
long as the usual method. It requires
relentless pursuit of that simplicity
even when obstacles appear which
would seem to stand in the way of
that simplicity.”
T. H. Nelson
The Home Computer Revolution, 1977
2
What is the User Interface?
A means for human
beings to interact with
computer-based tools
and messages.
3
What are the tools and messages?
• Tools
– home appliances and devices
– office productivity tools
– products people use while
traveling between home and
work.
4
What are the tools and messages?
• Messages
– Computer-supported
communication
– Story-telling and conversations
• in groups or alone
• Synchronous or Asynchronous
• the other participant may be a person
or a machine.
5
Goal of the User Interface
Make the user's experience
productive, efficient,
pleasing, and humane.
6
Early computers were
– usable only by people who
devoted great effort to master
the technology.
Today user interfaces
– help produce business success
stories and Wall Street sensations.
7
What
characteristics
do you look for in
a user Interface?
8
The Eight Golden
Rules of
Interface Design
(CRUCIFEM)
9
Strive for Consistency
Users should not have to wonder
whether different words,
situations, or actions mean the
same thing.
Follow consistent conventions.
10
Easy Reversal of Actions
Users often select functions by
mistake and need an
emergency exit
Interface should support
undo and redo
11
Universal Usability
Consider the needs
of diverse users
–Novice to expert users
–Age ranges
–Disabilities
How can one interface address the
needs of a novice and expert user at
the same time?
12
Move towards Completion
Sequence of actions should be
organized into groups with a
beginning, middle and end.
13
Support an Internal Locus
of Control
The user should feel in control of the
environment.
The environment should NOT include:
– surprising interface actions
– tedious sequences of data entries
– inability to obtain or difficulty in
obtaining necessary information.
The above items quickly build
anxiety and dissatisfaction.
14
Offer Informative Feedback
For every action, there
should be some sort of
system feedback.
15
Prevent Errors
As much as possible, the system should be
designed so users can’t make serious
errors.
How can a system
be designed to do this?
(Think back to part one)
The system should detect errors when
made and offer simple instructions for
recovery.
16
Reduce
Short Term Memory Load
Minimize the Users Memory Load
– Rule of Thumb:
Humans can remember 7±
chunks of information at a time
Keep displays simple
17
Becker’s Veterinarian Clinic
Let’s look at the completed
database again. This time we
will evaluate the user interface
18