Usability Measurement Lecture 3

Lecture 3: Usability: Measurement

• Usability is measured.
• Nielsen's 10 Usability Heuristics for User Interface Design are a set of principles for good user interface design.

Nielsen's 10 Usability Heuristics for User Interface Design

• Visibility of system status: The system should keep users informed about what is happening through feedback in a reasonable time.
• Match between system and real world: The system should use words, phrases, and concepts familiar to the user, not system-oriented terms. It should follow real-world conventions and arrange information in a logical order.
• User control and freedom: Users should have a way to easily leave unwanted states ("emergency exit") without unnecessary steps. Undo and redo are examples of effective user controls.
• Consistency and standards: The system should use consistent words, situations, and actions; it should follow platform conventions.
• Error prevention: Prevent errors from occurring in the first place, or provide clear instructions and feedback to help users avoid them if an error happens
• Recognition rather than recall: Make objects, actions, and options visible. Users should not need to remember information from one part of the dialogue to another. Instructions should be easily findable and visible
• Flexibility and efficiency of use: Include shortcuts for experienced users, but still be usable by novice users.
• Aesthetic and minimalist design: Avoid irrelevant information and keep only the essential data elements to maintain clarity.
• Help users recognize, diagnose, and recover from errors: Provide helpful error messages to help users determine the issue and suggest solutions.
• Help and documentation: Any help and info available should be easy to find and focus on the user's task, provide concrete steps, and should not be too large.

Example: Match Between System and Real World

• The design should use phrases/words that are familiar to the user. Instead of using system-oriented terms (e.g., "log in procedure"), simple and common words (e.g., "sign up") are used.

Example: User Control and Freedom

• Users will often choose system functions by mistake, need a clear way to undo these mistakes, or "emergency exit".
• An example of user control is the "undo" feature.

Example: Consistency and Standards

• Icons and symbols should have consistent meaning across an application. For example, a trashcan icon should always mean "delete."

Example: Error Prevention

• Error messages should use clear and concise language, highlighting the problem to the user. Messages should also suggest solutions to the problem. For instance, if a user entered an incorrect email address, error messages would state clearly ("The email address must include@").

Example: Recognition Rather Than Recall

• Users should not need to remember steps from one part of an application/dialogue to another.
• Instructions for the application should be helpful and be readily available to the user.

This quiz covers the essential principles of measuring usability in user interface design, focusing on Nielsen's 10 Usability Heuristics. Each heuristic emphasizes the importance of creating intuitive and user-friendly systems. Test your knowledge and understanding of these fundamental concepts in usability.