Chapter 10: Usability (TEST 2) Flashcards
What is Usability
The International Organization for Standardization (ISO) defines usability as
“the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction”
Three criteria to judge usability of a product
Effectiveness, Efficiency, and Satisfaction
Effectiveness
Accuracy and completeness in regards to users’ specific goals
completed tasks, number of errors, quality of the outcome, recall, spatial accuracy
Efficiency
Resources required to achieve users’ goals
Time to complete, mental effort (cognitive load), patterns of usage, number of steps to complete, input rate
Satisfaction
Freedom from discomfort and positive attitudes towards the user of the product
surveys, ease of use, perception
Steps to creating a usability test
- Identify Users
- Identify Task
- Identify Measures
- Create Your Environment
Factors to consider when Identifying your Task
Can be performed in a reasonable time
Represents typical users’ goals
Needs to be measurable and can be validated
Factors in Identifying Measures
Discrete: # of errors
Continuous: time to complete task
Navigate to ____ | # of clicks
Find ___________ | Time in takes
What is an interface
A point where two systems, subjects, organizations, etc. meet and interact
The interface is how the user gives commands to the computer/technology and how the computer/technology gives information back to the user
Jakob Nielsen’s Ten Usability Heuristics
- Visibility of System Status - interactive mall map
- Match between System and Real World -stovetop controls match to each burner
- User Control and Freedom - emergency exits
- Consistency and Standards - conventional design is intuitive (check-in desk at the front)
- Error Prevention - guard rails
- Recognition rather than Recall - Avoid making users remember
- Flexibility and Efficiency of Use - Shortcuts hidden from novice users
- Aesthetic and Minimalist Design - no information is irrelevant
- Recognize, Diagnose, and Recover from Errors - errors are expressed correctly
- Help and Documentation - information kiosk
My favorite three heuristics
- Aesthetic and Minimalist Design
- Flexibility and Efficiency of Use
- Recognition Rather than Recall