MidTerm1 Flashcards
Effectiveness
A usability goal:
- Can the user complete their goals with the system?
- Is the system doing what it is supposed to do?
Efficiency
A usability goal:
- How much time/number of steps will it take the user to perform their tasks?
- Less time/steps means more efficient.
Criteria: time/# of operations to complete a task.
Safety
A usability goal:
- Prevent user from making serious/unrecoverable errors.
- Provide means of recovering from errors.
- Undo options/confirmation dialog.
Criteria: # of errors/time to recover from error.
Utility
A usability goal:
- Sufficient functionality to accommodate range of user tasks.
- Does it provide sufficient functionality for users to carry out tasks as naturally as possible?
Criteria: Availability of core tasks or, offer as many related tasks as possible. (accounting software, paint tool)
Learnability
A usability goal:
- How easy is it for the user to adapt to the system?
- The more learnability, the faster a user can complete tasks.
- Can primary and secondary tasks be learned quickly and easily?
Criteria: Time taken to learn a task, errors made when learning a task.
Memorability
A usability goal:
- Once a system is learned, how easy is it to remember how to use it?
- Important for systems that will be used infrequently.
- Should be designed to have meaningful icons/menus items etc.
- Will users remember all the steps needed for carrying out a task?
Criteria: Amount of Time/errors made when carrying out a task after system is learned.
User Experience Goals
- Satisfying: Productive
- Helpful: Clueless but still made it through
- Enjoyable: No frustrations
- Aesthetically Pleasing: Subjective
- Motivating: Did not feel like giving up
- Supportive of Creativity: Artistic tools
- Entertaining: Games
- Rewarding: Sense of productivity
- Fun: excited about using it again
Visibility
A design principle:
- The more visible an element is, the more likely users will know about them and how to use them.
- Advocates the use of making core user functions clearly apparent, hides secondary user functions.
- Visible properties guides users into what to do next.
Problem: Not being able to see how to use a device.
Feedback
A design principle:
- Continuously inform the user about the system’s state.
- How is it interpreting the user’s input?
- Users should at all times be aware of what is going on.
Response time of feedback:
-0.1 second max: Perceived as instantaneous
-.07 second max: Minimal time for motor reactions
10 seconds: Limit for keeping user attention focused on dialog.
>10 seconds: User will want to perform other tasks while waiting, so let them know!
Constraints
A design principle:
-Restricts the kinds of user interactions that can take place for any given type of interaction.
-Constraining users to only enter a certain amount, or type of input, or letting them only click on certain buttons etc. (Like when menu options are grayed out,
or a date picker or a submission form)
Mapping
A design principle:
- Relates controls to the intuitive understanding of how they should be used.
- Relationship of controls and their effects should be clear. (i.e. arrows on a scroll bar.)
Consistency
A design principle:
Aesthetic:
-Style and appearance are repeated to enhance recognition
-Communicates membership and sets emotional tone (i.e.logos on cars)
Functional:
- Meaning and action are consistent to improve learnability and understanding
- Consistent use of symbols to represent similar concepts leverages prior knowledge to make things easier to user. (i.e. Traffic lights)
Internal:
- The consistency of elements within the system.
- Cultivates trust and communicates that a system is designed as a whole rather than separate pieces (i.e. Microsoft Office)
External:
- Consistent with other elements in the environment
- Extends benefit of internal consistencies across multiple independent systems.
- Difficult to achieve because different systems often use different design standards.
Affordance
A design principle:
- On a basic level, it means “To give a clue”
- Perceived and actual properties of an object that give clues on how to operate them.
(i. e. chairs for sitting, knobs for turning buttons for pushing, menu options for selecting etc.)
Simplicity
A design principle:
- Common tasks should be easy to perform
- Less is more. Provide only the necessities
- Remove or hide irrelevant or rarely needed information
Matching
A design principle:
- Match between system and real world
- Speak the user’s language
- Terminology based on users’ language for a task.
(i. e. don’t use code or very technical language for displaying information) - Use meaningful mnemonics, icons, and abbreviations
