IACT 701
Theory of �Interaction Design
Usability Heuristics
Heuristics
Enabling a person to �discover or learn something for themselves.
Mental shortcuts to ease the �cognitive load of making a decision.
"The 10 most
general principles for interaction design. �
They are called 'heuristics' because they are �more in the nature of rules of thumb than �specific usability guidelines."
Jakob Nielson
Usability OG
Usability Heuristics
Usability Heuristics
Usability Heuristics | Visibility of System Status
Visibility of System Status
The system should always �keep users informed about what is going on, �through appropriate feedback within reasonable time.
Usability Heuristics | Visibility of System Status
Show: Time
Feedback depends on response time:
< 1 sec: just show outcome
�~ 1 sec: feedback that �activity is underway
�>> 1 sec: Show fractional �progress; time
Usability Heuristics | Visibility of System Status
Show: Space
Usability Heuristics | Visibility of System Status
Show: Change
Usability Heuristics | Visibility of System Status
Show: Change
Usability Heuristics | Visibility of System Status
Show: Action
Usability Heuristics | Visibility of System Status
Show: Next Steps
Usability Heuristics | Visibility of System Status
Show: Completion
Usability Heuristics | Match Between System & Real World
Match Between System & Real World
The system should speak the users' language, �with words, phrases and concepts familiar to the user, �rather than system-oriented terms.
�Follow real-world conventions, making information appear in a natural and logical order.
�Familiar metaphors
Usability Heuristics | Match Between System & Real World
Matches
Usability Heuristics | User Control
User Control & Freedom
Users often choose system functions by mistake �and will need a clearly marked "emergency exit" �to leave the unwanted state.
Without having to go through an extended dialogue. �Support undo and redo, and review and edit.
Usability Heuristics | User Control
User Control: Review
Usability Heuristics | User Control
User Control: Edit
Usability Heuristics | User Control
User Control
Usability Heuristics | Consistency & Standards
Consistency & Standards
Users should not have to wonder whether different words, situations, or actions mean the same thing.
Follow platform conventions.
Usability Heuristics | Consistency & Standards
Consistency: Clickable Elements
Usability Heuristics | Consistency & Standards
Consistency: Navigation
Usability Heuristics | Error Prevention
Error Prevention
Even better than good error messages is a careful design which prevents a problem from occurring in the first place.
Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
Usability Heuristics | Error Prevention
Error Prevention: Prevent Data Loss
Usability Heuristics | Error Prevention
Error Prevention: Prevent misinterpretation
Usability Heuristics | Error Prevention
Error Prevention: Bad Input
Usability Heuristics | Help Users Understand and Recover from Errors
Help Users Recover from Errors
Error messages should:
Usability Heuristics | Help Users Understand and Recover from Errors
Error Recovery: Clarity
Usability Heuristics | Help Users Understand and Recover from Errors
Error Recovery: Alternative Solution (no dead ends)
Usability Heuristics | Help Users Understand and Recover from Errors
Error Recovery: Alternative Solution (no dead ends)
Usability Heuristics | Recognition Rather Than Recall
Recognition Rather Than Recall
Minimize the user's memory load �by making objects, actions, and options visible.
The user should not have to remember �information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.
Usability Heuristics | Recognition Rather Than Recall
Recognition Rather Than Recall
What is your professor’s full name?
Usability Heuristics | Recognition Rather Than Recall
Recognition Rather Than Recall
What is your professor’s full name?
Usability Heuristics | Recognition Rather Than Recall
Recognition: Previews
Usability Heuristics | Recognition Rather Than Recall
Recognition: Previews
Usability Heuristics | Flexibility & Efficiency of Use
Flexibility & Efficiency of Use
Accelerators—unseen by the novice user—may often �speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users.
Usability Heuristics | Aesthetic & Minimalist Design
Aesthetic & Minimalist Design
Dialogues should not contain information which �is irrelevant or rarely needed.
Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.
Usability Heuristics | Aesthetic & Minimalist Design
Aesthetic & Minimalist Design
Usability Heuristics | Aesthetic & Minimalist Design
Usability Heuristics | Aesthetic & Minimalist Design
Usability Heuristics | Help & Documentation
Help & Documentation
Even though it is better if the system can �be used without documentation, �it may be necessary to provide help and documentation.
Any such information should be easy to search, �focused on the user's task, list concrete steps to �be carried out, and not be too large.
IACT 701
Theory of �Interaction Design
Usability Heuristics