Cognitive Science Project
Usability
Usability
- How well can a person utilize an interface?
- Can a task be completed?
Goals of User-Interface Design (What is the professional
looking for in successful design)
- Time to learn interface
- Speed of performance in carrying out typical tasks
- Rate of errors by user
- Retention over time
- Subjective Satisfaction - this is the key in many cases!
Cognitive and Perceptual Abilities that can effect the
usability of a design
- Short-term memory
- Long-term memory and learning
- Problem solving
- Decision making
- Attention and set
- Search and scanning
- Time perception
Are users stupid?
- Even the most expert users prefer simplicity rather than
complexity!
- People with different strengths and weaknesses are going to
have different needs when it comes to making an interface
usable.
- The goal is to make the interface usable for the majority of
the population that uses it!
Cultural and International Design Concerns
- Is the system going to be usable for the international
community?
- Characters, numerals, special characters, and
diacriticals
- Left-to-right vs. Right to left, vertical or horizontal
- Date and time formats
- Numeric and currency formats
- Weights and measures
- Telephone numbers and addresses
- Names and titles (Mr., Ms., Dr., etc)
- Identification numbers, passports numbers
- Capitalization and punctuation
- Language and Grammar
- Word Ending Syntax
- Word Order Syntax
- Etiquette, policies, tone, formality, metaphors
What are the design issues for persons with
disabilities?
Use the Eight Golden Rules of Interface Design
- Strive for consistency
- Enable frequent users to use shortcuts
- Offer informative feedback
- Design dialogs to yield closure
- Offer error prevention and simple error handling
- Permit easy reversal of actions
- Support internal locus of control
- Reduce short-term memory load
- simplicity better
- seven-plus or minus-two
Getting the User's Attention
- Intensity
- Marking - bold, etc
- Size - Large vs.
Small
- Choice of fonts- Is this
easy to read?
Goals of Usability Testing
- Determine the needs of a user
- Simplicity
- Reach a wide range of users
- Quality
- Completion of tasks
- Satisfaction - This is the key
Usability of GUI Operating Systems
- Metaphors
- Menus
- Consistancy
Web Sites
Interface Hall of Shame
http://www.iarchitect.com/mshame.htm
Fixing Your Web Site
http://www.fixingyourwebsite.com/
Usability (government)
http://usability.gov/index.html
Good Web Design?
http://www.library.cmu.edu/Unofficial/WebCourse/webdesign.html
Color and Blinking
http://www.physics.brocku.ca/oapt97/webtut/principles.html
Is this good or bad?
http://www.geocities.com/invokingirene/LIST.html
Color Example
Web Page Created by Jennifer
L. Rowsam, 2002