FIT3175 Lecture Notes - Lecture 8: Usability, User Interface, Cognitive Walkthrough
15 Jun 2018
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Department
Course
Professor
Week 8 - Usability Evaluation
Nielsen’s view of Usability
●Learnability :
○How easy is it for users to accomplish basic tasks the first me they encounter it?
●Efficiency :
○Once user’s have learned the design, how quickly can they perform tasks?
●Memorability :
○How easy can a user re-establish proficiency when they revisit the design?
●Errors
○How many errors do users make?
○How server are those errors?
○How easily can users recover from mistakes?
●Satisfaction
○How pleasant is it to use the design?
●Utility
○Where it provides the features you need - does it do what is needed?
●Usefulness : usability + ulity
Whiteney Quesenbery’s 5E’s of Usability
They are measurable.
●Effective : completeness and accuracy with which users achieve their goals
●Efficient : speed and accuracy with which users achieve their goals
●Engaging : the degree to which the product is pleasant and sasfying to use
●Error-tolerant : how well the system helps prevent errors and enables error recovery
●Easy to learn : how easy is the system to use unassisted / user to remember how to use
Usability Goals
●Depends on the system and user populaon
●Depends on the resources available (me, money, skills)
Usability Engineering
A more formal process to tesng usability principles
1. Define goals
2. Specify quanfiable measure of usability
3. Set limits to the specified measures
4. Assess measurements against the limits
5. Analyse the impact
6. Incorporate user feedback
Usability Evaluation
●Applied experimentaon in which developers check that the system being developed is
usable
●Aims to improve usability
Document Summary
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