1. Chapter 9 Design guidance and design rationale

2. UIDE Chapter 9 Sources of Design Guidance Standards Standards –User interface standard Design Guidelines Design Guidelines Style Guide Style Guide

3. UIDE Chapter 9 User Interface Standards Official, publicly available documents that define standards for user interface design Official, publicly available documents that define standards for user interface design –ISO 9241 – Ergonomic requirements for office work with visual display terminals –ISO 14914 – Software ergonomics –ISO 13407 – Human-centered design process –ISO 20282 – Operation of everyday products

4. UIDE Chapter 9 ISO 13407 Human-Centered Design Processes for Interactive Systems Benefits: Benefits: –Systems are easier to understand and use –Discomfort and stress are reduced –User satisfaction is improved –Productivity and efficiency is improved –Quality, aesthetics and impact are improved

5. UIDE Chapter 9 ISO 13407 Human-Centered Design Processes for Interactive Systems Essential Elements Essential Elements –Active involvement of and clear understanding of users –Appropriate allocation of functions between users and technology –Iteration of design solutions –Multidisciplinary design perspective Next: Style Guides Next: Style Guides

6. UIDE Chapter 9 Style Guides A typical guide includes: A typical guide includes: –Description of required interaction styles and user interface controls –Guidance on when and how to use the various styles or controls –Illustrations of styles and controls –Screen templates

7. UIDE Chapter 9 Commercial Style Guides Apple Interface Guidelines Apple Interface Guidelines Apple Interface Guidelines Apple Interface Guidelines Microsoft Windows XP UI Guidelines Microsoft Windows XP UI Guidelines Microsoft Windows XP UI Guidelines Microsoft Windows XP UI Guidelines IBM’s Common User Access IBM’s Common User Access IBM’s Common User Access IBM’s Common User Access Motif Style Guide Motif Style Guide Motif Style Guide Motif Style Guide Sun Microsystems’ Java Look and Feel Sun Microsystems’ Java Look and Feel Sun Microsystems’ Java Look and Feel Sun Microsystems’ Java Look and Feel K Desktop Environment K Desktop Environment K Desktop Environment K Desktop Environment

8. UIDE Chapter 9 Customizes Style Guides Helps focus on design issues early Helps focus on design issues early Enables use of principles and guidelines Enables use of principles and guidelines Steer decision making and serve as record Steer decision making and serve as record Ensures consistency Ensures consistency

9. UIDE Chapter 9 Design Principles: Simplicity, Structure, Consistency, and Tolerance Design Principles: Simplicity, Structure, Consistency, and Tolerance –Simplicity –Structure –Consistency –Tolerance

10. UIDE Chapter 9 Simplicity

11. Structure Organization of the UI in a meaningful way Organization of the UI in a meaningful way

12. UIDE Chapter 9 Consistency Uniformity in appearance, placement, and behavior Uniformity in appearance, placement, and behavior

13. UIDE Chapter 9 Tolerance Prevent user from making mistakes Prevent user from making mistakes –Prevention –Recoverability Forward error recovery - system accepts the error and helps the user to accomplish their goal Forward error recovery - system accepts the error and helps the user to accomplish their goal Backward error recovery – undo the effects of the previous interaction Backward error recovery – undo the effects of the previous interaction

14. UIDE Chapter 9 Accessibility Accessibility –The Principles of Universal Design –W3C Web Content Accessibility Guidelines –Section 508 –The Limitations of Guidelines

15. UIDE Chapter 9 7 Principles of Universal Design Equitable use – useful to diverse abilities Equitable use – useful to diverse abilities Flexibility in use – accommodates a wide range Flexibility in use – accommodates a wide range Simple and intuitive use – easy to use & learn Simple and intuitive use – easy to use & learn Perceptible information – communicates effectively Perceptible information – communicates effectively Tolerance for error - minimizes Tolerance for error - minimizes Low physical effort – minimum fatigue Low physical effort – minimum fatigue Size and space for approach and use Size and space for approach and use

16. UIDE Chapter 9 W3c Web Content Guidelines W3c Web Content Accessibility Guidelines W3c Web Content Accessibility Guidelines W3c Web Content Accessibility Guidelines W3c Web Content Accessibility Guidelines –14 general principles of accessible design 1.Provide alternatives to auditory and visual content 2.Don’t rely on color alone 3.Use markup and style sheets properly 4.Clarify natural language usage 5.Create tables that transform gracefully 6.New technology pages transform gracefully

17. UIDE Chapter 9 W3c Web Content Guidelines 7. Ensure user control of time-sensitive content changes 8. Ensure direct accessibility of embedded user interfaces 9. Design for device independence 10. Use interim solutions (for older browsers to function) 11. Use W3C technologies and guidelines 12. Provide context and or entation information 13. Provide clear navigation mechanisms 14. Ensure that documents are clear and simple

18. UIDE Chapter 9 Section 508 Federal Guidelines Federal Guidelines Federal Guidelines Federal Guidelines

19. UIDE Chapter 9 Design Rationale Design Rationale –The Benefits of Recording Design Decisions Maintains decision process Maintains decision process Valuable to justify design decisions Valuable to justify design decisions –How to Record Design Decisions Document only key decisions Document only key decisions Tabular design is easiest to comprehend Tabular design is easiest to comprehend Categorized by date Categorized by date