1. Anti-mac Interface Dona Gentner Jakob Nielsen [Sun Microsystems]

2. 1 Background The Macintosh designed to be "the computer for the rest of us“ "the first personal computer good enough to be criticized." Alan Kay Prevailing constraints: Audience – naïve users Narrow range of applications – undiscovered territory Weak computational resources Highly impoverished communication channels No networking How about now?

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4. 3 Macintosh human interface design principles Metaphors Direct Manipulation See-and-Point Consistency WYSIWYG User Control Feedback & Dialog Forgiveness Perceived Stability Aesthetic Integrity Modelessness

5. 4 Macintosh human interface design principles: Metaphor Desktop, village, building metaphors Clunky indirectness Navigationally cumbersome E.g. Phelp’s tractor (1901) E.g. Mac multiple trashcans Can limit designer’s creativity E.g. Sun documentation Invalid assumptions regarding user audience experiences

6. 5 Macintosh human interface design principles: Direct Manipulation Works well for small number of objects Difficult to direct high-level operations E.g. selecting a range of files of certain characteristics Operating at atomic level only Scripting mechanism required E.g. Photoshop actions Constrained to precision of hand/eye/mouse Language and maths can be more precise Users may not know what to manipulate Willing to delegate control to ‘single-click’ operation

7. 6 Macintosh human interface design principles: See-and-Point Interaction by pointing and clicking on objects faculty with expressive language lost Keyboard modifiers equivalent to grunts Cannot communicate with objects that Are not immediately visible  E.g. all files less than 1 week old Don’t yet exist E.g. future messages from my boss Are unknown E.g. any guides to restaurants in Boston

8. 7 Macintosh human interface design principles: Consistency Basic advantage is the hope that learning will be reduced if objects with a similar function always look and behave the same How about pens? Rich and fine-grained representation of objects in the real world helps us distinguish

9. 8 Macintosh human interface design principles: WYSIWYG Usually WYSIATI (What You See Is All There Is) Document’s rich semantic structure lost E.g. italicised word could indicate biblio entry, quote, or simple emphasis SGML preserves semantic attributes Not appropriate for modern communications E.g. same info presented on desktop, mobile browsers, screen reader for disabled etc.

10. 9 Macintosh human interface design principles: User Control User alone should initiate and control actions What about delegation as in real-world? People bad at vigilance tasks E.g. backups, saving document, forgetting meetings We participate in the Internet with little control

11. 10 Macintosh human interface design principles: Feedback and Dialog The computer interface should provide the user with clear and immediate feedback on any actions initiated by the user Master-Apprentice model preferable Provide a spectrum of feedback Diminish feedback as experience grows ‘No news is good news’

12. 11 Macintosh human interface design principles: Forgiveness States that user actions should generally be reversible and that users should be warned if they try to do something that will cause irreversible data loss. E.g. Mac Trash can circular problem Underlying problem is meager understanding of the interaction history Stateless interface is inadequate Computer needs to build a deeper model of our intentions and history.

13. 12 Macintosh human interface design principles: Perceived Stability Elements in the computer interface should not be changed without the user's involvement “Children like stability” Computer games eschew stability Internet thrives on ‘new-ness’ Growing maturity of users less insecurity

14. 13 Macintosh human interface design principles: Aesthetic Integrity States that the graphic design of the interface should be simple, clean, and consistent Partly due to limited expressiveness of current computers E.g. consider city designed by a single architect with a consistent visual appearance Difficult to navigate and boring Richer more detailed designs are Interesting Provide landmarks

15. 14 Macintosh human interface design principles: Modelessness Computer interface should not have distinct modes that restrict the user's actions depending on the mode he or she is in However user cannot cope with everything at once need the interface to narrow their attention and choices so they can find the information and actions they need at any particular time real life is highly moded