Week 1 Flashcards
What is Usability?
The degree to which something is able or fit to be used.
LEAF Criteria Shackle, 1986/1991
Learnability
Effectiveness
Attitude
Flexibility
Learnability - LEAF
Users must be able to learn to use the system after a certain amount of training.
Effectiveness - LEAF
Use of a system in a number of environments, within a certain time, and within error limits.
Attitude - LEAF
Positive attitudes towards using the system and levels of tiredness or discomfort are kept to a minimum.
Flexibility - LEAF
User performance must not degrade beyond a certain limit across tasks and environments.
What concept did Booth (1989) think needs to be incorporated into the definition of usability?
Usefulness
3 areas for Nielsen (1993) - framework for usability?
1) System acceptability
2) Practical acceptability
3) Usefulness/Usability
System acceptability - Framework for Usability
Social acceptability and Practical acceptability
Practical acceptability - framework for usability
1) Utility
2) Cost
3) Comparability
4) Reliability
5) Usefulness/Usability
Usefulness/Usability - Framework for Usability
1) Efficient to use
2) Easy to learn
3) Easy to remember
4) Few errors
5) Subjectively pleasing
Jordan (1995) extention on Nielsen’s usability concepts
Include system potential and system reusability.
System potential
Achieving optimal performance - optimal level of effectiveness, efficiency and satisfaction that is possible (the upper limit of experienced user performance).
Reusability
Level of performance after non-use - the effectiveness, efficiency and satisfaction with which the specified users can achieve specified tasks with a particular product after a comparatively long period away from these tasks (decrement in performance).
Marazano (1998) - emotions associated with products?
Product properties that influence the level of pleasure/displeasure.
‘Ease of use’
Something that significantly impacts our emotional reaction to a product.
5 E’s? - What makes technology useable?
- Effective - the completeness and accuracy with which users achieve specific goals.
- Efficient - the speed (with accuracy) in which users can complete the tasks for which they use the product.
- Engaging - how pleasant, satisfying, or interesting the piece is.
- Error tolerant - how well the product prevents errors and helps users recover from any errors that do occur,
- Easy to learn - how well the product supports both initial orientation and deeper meaning.
What does confound mean?
Things we can control for effect.
6 Important User Issues:
1) Cognitive and Perceptual
2) Personality Differences
3) Cultural and Environmental Diversity
4) Users with diabetes
5) Senior citizens and children
6) Psychic abilities. Psychical workplace.
