This document discusses software usability and user interface design. It defines usability as the ease of learning, use, remembering, satisfaction with, efficiency of, and effectiveness of a system. Usability engineering is described as processes used to build usability into products throughout the design lifecycle while maintaining a focus on the user. Common web site usability problems like navigation, structure, and layout are also outlined. The document advocates for user-centered design and applying usability principles to improve the user experience.

1. Software Construction
(USABILITY and
USER INTERFACE DESIGN)

2. Usability
What is Usability?
Ease of learning
Ease of use
Ease of remembering
Subjective satisfaction
Efficiency of use
Effectiveness of use

3. Usability Engineering
Usability Engineering (UE):
Processes to build “Usability” into
products
Various methods can be used throughout
the design lifecycle
Methods can be incorporated into design
process easily
Methods maintain focus on user
throughout design

4. Why Isn’t UE Done Regularly?
Developers believe
it takes too long
is too expensive
is not critical to development
they can afford to learn about user
problems during “live” use
Also developers may not know how to
do it

5. Benefits of UE to an Organization
Reduce training costs
Reduce development costs
Identify and fix problems early
Reduce support costs; minimize need for
support personnel/help desks
fixes, maintenance, upgrades
Enhance organization’s reputation - positive
“word-of-mouth” trade
Larger numbers of “hit” and “return visit”
rates

6. Benefits of UE to the User
Less time to complete work
Greater success with tasks
Increased user satisfaction
“The fun theory”

7. Typical Web-site Usability Problems
Navigation
Knowing where you are
Finding what you want
Structure of web site
Layout
Needs sufficient white space
Use of large graphics
“The Google problem”

8. User Centered Design
UCD is a dialog between the customer and
the designer
Rules of thumb:
Get to know and understand the users.
Build an application, applying usability
principles.
Test designs by observing users in a real work
setting (environment and work load).

9. Usability Principles

10. Mini-Exercise
Apply the principles to a web-site of your
choosing, or try:
http://www.lingscars.co.uk
http://www.constellation7.org
http://www.sixtiespress.co.uk/
http://www.leoneck.ch
http://www.dsrny.com/

11. GUI Design is Multi Disciplinary
A team includes
Analyst
Designer
Technology expert
Graphic artist
Social and behavioral scientist
Programmer

12. Basic Principles
Assume users
Have not read the manual
Have not attended training
Do not have external help readily at hand
So…
All controls should be clear and understandable
and placed in an intuitive location on the screen.

13. Usability Design Process

14. Use Scenario Development
You already know about use cases
Use scenarios are just a single thread
through a use case – much simpler!

15. UI Structure/Flow of Control