The main idea of usability is that a system shall be designed with (generalized) users’ psychology and physiology in mind, to make that system:
- more efficient to use, so it takes less time to accomplish particular tasks
- easier to learn
- more satisfying to use
Definitions:
Capability of a product to be used by specified users to exchange information between a user and an interactive system via the user interface to complete the intended task. ISO-25010, v2022
The capacity of a system to provide a condition for its users to perform the tasks safely, effectively, and efficiently while enjoying the experience. Wikipedia
Typical Acceptance Criteria
Scenario Response Measures from [Bass et al.]
The system should:
- provide the user with the features needed
- anticipate the user’s needs
- provide appropriate feedback to the user
The system’s response might be measured in one or more of the following:
- task time
- number of errors
- learning time
- ratio of learning time to task time
- number of tasks accomplished
- user satisfaction
- gain of user knowledge
- ratio of successful operations to total operations
- amount of time or data lost when an error occurs
What Stakeholders mean by usable
Stakeholder | (potential) Expectation for usable |
---|---|
User | see the criteria above. More specifically: * functional-completeness * accessibility * correctness * visual and behavioural consistency * understandability * ease-of-use * functional-suitability * learnability * nice user-experience (maybe even more) |
Product-Owner | - |
Management | - |
Developer | * understandable source-code and dependencies * an appropriate technology-stack * no (or at least predictable) side-effects when changing the system |
Tester | * testability * predictable test behaviour |
Admin | * easy to deploy and install, * installability * deployability |
Domain-Expert | - |
Others | - |
Qualities tagged with #usable
- Accessibility
- Accuracy
- Adaptability
- Appropriateness-recognizability
- Availability
- Backward compatibility
- Clarity
- Code Readability
- Coherence
- Compatibility
- Compliance
- Conciseness
- Configurability
- Consistency
- Correctness
- Customizability
- Ease of Use
- Fault tolerance
- Faultlessness
- Features
- Functional appropriateness
- Functional completeness
- Functional correctness
- Functional suitability
- Functionality
- Graceful degradation
- i18n (Internationalization)
- Internationalization
- Interoperability
- Latency
- Learnability
- Legal Requirements
- Legibility
- Localizability
- Operability
- Preciseness
- Precision
- Readability
- Recoverability
- Self-descriptiveness
- Simplicity
- Standard Compliance
- Suitability
- Understandability
- Usability
- User assistance
- User engagement
- User error protection
- User experience
- User interface aesthetics
Requirements tagged with #usable
- Access find function in three seconds
- Ease of Use
- Usability
- User experience
- Accurate estimate of insurance contract rate
- Accuracy
- Functional correctness
- Preciseness
- Precision
- Reliability
- Available 7x24 with 99% uptime
- Availability
- Operability
- Reliability
- User error protection
- Compliance with UI styleguide
- Compliance
- Usability
- User experience
- Consistent keyboard shortcuts
- Consistency
- Usability
- User assistance
- User experience
- Core functions can be used on multiple OSs
- Compatibility
- Flexibility
- Portability
- Detect inconsistent user input
- Consistency
- Usability
- User assistance
- User experience
- Easily understandable acceptance test cases
- Consistency
- Efficiency
- Maintainability
- Suitability
- Easily understandable generated code
- Code Readability
- Legibility
- Maintainability
- Readability
- Understandability
- Expressive error messages
- Fault isolation
- Graceful degradation
- Hazard warning
- Usability
- User assistance
- User experience
- Interruptable backend process
- Time behaviour
- Usability
- User experience
- Near instant search results
- Efficiency
- Speed
- Time behaviour
- Restored to fully functional state 12h after complete failure
- Availability
- Mean time to recovery
- Operability
- Reliability
- Usable Despite Color Blindness
- Accessibility
- Compliance
- Usability
- User experience
- Usable With Gloves
- Compliance
- Usability
- User experience
- User Interface can be used in Current Browsers
- Compatibility
- Flexibility
- Interoperability
- Portability