Method for evaluating usability using simple heuristics:

• Developed by J. Nielsen & R. Molich

• Small team of evaluators independently look for usability problems (1-2 hours per person)

• Each evaluator checks whether list of design heuristics are violated by the interface design
• inspect each screen
• inspect flow from screen to screen
• Then meet and compare findings

• Nielsen: 5 evaluators typically can find about 75% of usability problems
• if they have more expertise in UI, then fewer needed
• moderately effective without requiring lots of time or resources or real users

• disadvantages: not based on user tasks so may not uncover problems that users will encounter

• Simple and natural dialogue
• Simple: no irrelevant or rarely used information
• Natural: order matches user's task order,
• Speak the user's language
• use concepts from user's world, not system designer's
• Minimize user memory load
• don't make user remember things from one action to the next
• leave information on screen until no longer needed
• Be consistent
• action sequences learned in one part of system should apply in other parts
• Provide feedback
• let users know what effect their actions have on system
• Provide clearly marked exits
• if users get into part of system that doesn't interest them, they should be able to get out quickly without damaging anything.
• Provide shortcuts
• help experienced users avoid lengthy dialogues and informational messages they don't need
• Good error messages

• let the user know what the problem is and how to correct it

• Prevent errors

• whenever you discover an error message, ask if that error could have been prevented.

"New Improved" 10 Heuristics:

1. Visibility of system status:

• Keep user informed about what is going on within reasonable time

• Speak the user's language, follow real-world conventions, information appears in natural and logical order

• Support undo and redo

5. Error prevention

6. Prevention is better than good error messages!

7. Recognition rather than recall

• Make objects, actions and options visible. Instructions for use of the system should be visible or easily retrievable whenever appropriate

8. Flexibility and efficiency of use

9. Aesthetic and minimalist design

10. Help users recognize, diagnose and recover from errors

11. Help and documentation
 
 
 

In-class exercise: heuristic analysis of GUI