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
Enable users to perform their tasks safely, effectively and efficiently while enjoying the experience.
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
- Anticipated Workplace Environment
- Appearance
- Appropriateness-recognizability
- Availability
- Backward compatibility
- Clarity
- Code Readability
- Coherence
- Compatibility
- Compliance
- Conciseness
- Configurability
- Consistency
- Convenience
- 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
- Reproducibility
- 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