William H. Bowers – Metaphors, Idioms and Affordances Cooper 20

William H. Bowers – Agenda Interface Paradigms Interface Paradigms Implementation Centric Implementation Centric Metaphoric Metaphoric History of Metaphors History of Metaphors Limitations of Metaphors Limitations of Metaphors Global Metaphors Global Metaphors

William H. Bowers – Agenda Intuition, Instinct and Learning Intuition, Instinct and Learning Idiomatic Interfaces Idiomatic Interfaces Branding and Idioms Branding and Idioms Building Idioms Building Idioms Manual Affordances Manual Affordances

William H. Bowers – Interface Paradigms Implementation Centric Implementation Centric –Based on understanding how things work Metaphoric Metaphoric –Intuiting how things work Idiomatic Idiomatic –Learning how to accomplish things

William H. Bowers – Implementation Centric Widespread use in GUIs Widespread use in GUIs User must know internal workings User must know internal workings –One function per button –One dialog per module –Commands and processes echo internals

William H. Bowers – Metaphoric Relies on intuitive connections Relies on intuitive connections Visual cues between interface and function Visual cues between interface and function Better than implementation centric Better than implementation centric Generally overrated Generally overrated Picture represents purpose Picture represents purpose

William H. Bowers – Metaphoric Intuited through inference Intuited through inference Connections between objects Connections between objects Based on similarities Based on similarities Depends on language and knowledge Depends on language and knowledge

William H. Bowers – History of Metaphors Invented with GUI at Xerox PARC Invented with GUI at Xerox PARC First commercial success at Apple First commercial success at Apple –Restricted vocabulary –Direct manipulation –Rich visual objects –Matched screen to print resolution

William H. Bowers – Limitations of Metaphors Poor scalability Poor scalability Rely on assumed associations Rely on assumed associations Dependent on cultural backgrounds Dependent on cultural backgrounds Costly for intermediates and experts Costly for intermediates and experts Hard to find Hard to find Tie us to physical realm Tie us to physical realm

William H. Bowers – Global Metaphors Provide framework for all other metaphors Provide framework for all other metaphors Requires cognitive association Requires cognitive association Can be confining Can be confining

William H. Bowers – Intuition, Instinct and Learning Instinct Instinct –Hard wired –No conscious thought required –Reaction to startling noises Intuition Intuition –Based on prior knowledge –Consciously learned

William H. Bowers – Idiomatic Interfaces Based on learning of non-metaphorical representations Based on learning of non-metaphorical representations Not necessarily logical or representative Not necessarily logical or representative Can not be reasoned or intuited Can not be reasoned or intuited Quickly and easily learned Quickly and easily learned

William H. Bowers – Idiomatic Interfaces GUIs are largely idiomatic GUIs are largely idiomatic –Radio buttons –Close boxes –Drop down menus

William H. Bowers – Branding and Idioms

William H. Bowers – Building Idioms Restricted vocabulary Restricted vocabulary Keyboard is for data entry Keyboard is for data entry Mouse is used for commands Mouse is used for commands

William H. Bowers – Building Idioms Primitives Compounds Idioms Point, click, drag, keypress Double click, selection Delete, draw

William H. Bowers – Manual Affordances Coined by Norman Coined by Norman Appearance suggests use Appearance suggests use –Buttons are pushed –Handles are pulled –Door push plates are pushed We intuit how to use it We intuit how to use it The functionality is not obvious The functionality is not obvious Software must have labels or icons Software must have labels or icons

William H. Bowers – Questions & Discussion