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Human-Computer Interaction. Icons Direct Manipulation. Lecture Overview. Definition Advantages and disadvantages Factors affecting meaningfulness Form and function Design guidance Classification. Icons: Definition. Pictographic symbols - focus on essential features
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Human-Computer Interaction Icons Direct Manipulation
Lecture Overview • Definition • Advantages and disadvantages • Factors affecting meaningfulness • Form and function • Design guidance • Classification
Icons: Definition • Pictographic symbols - focus on essential features • Represent underlying • objects • data structures • processes in a form which corresponds to the real world • Can be entertaining, clever and visually appealing
Advantages of Icons • Recognition • Users remember meaning more easily than for command names • Searched and selected faster than text • Compactness • Can often convey meaning more rapidly than symbolic language • Use less space than text • More features can be presented on one screen
Advantages of Icons (Cont’d) • Comprehensibility • Can convey objects, data and actions • Universality • Relatively language- and culture-independent • Facilitates porting to international markets • Plenty available for re-use • Micons (moving icons or animated icons) • Can represent dynamic aspects • (No clear evidence better than static)
Disadvantages of Icons • Ambiguity • Dependent on user, task and context • Cannot completely replace words in some complex situations • Costly / difficult to design good new icons • Micons - if too many on screen, can be distracting and jerky in movement
Factors Affecting Meaningfulness of Icons • Context • Specific vs General • Easy --------- Difficult to deduce meaning • Tasks • Visual vs Verbal • Easy ----------Difficult to design
Tooltip Microsoft Excel Factors Affecting Meaningfulness of Icons • Text • Addition increases understanding - especially if abstract, vague, large icon set
Psion 3a Icons ‘More’ icon ‘More’ icon
Factors Affecting Meaningfulness of Icons • Concept • Concrete vs Abstract • Easy ---------- Difficult to design • Discriminable • From other icons
Range of Icon Functions (Rogers, 1989) Function Example Labeling Menu item Indicating System state Warning Error message Identifying File storage Manipulating Tool for zooming and shrinking Container Object for placing discarded objects Gestalt pattern Structure in programming language
Design of Icons • Poorly understood by computer professionals • Everyday icons are the subject of much research e.g. flight arrivals /departures • Trend towards higher quality graphics
Design Guidance • General HCI guidelines apply • Re-use / re-work existing designs • Test representation with users • Avoid symbols unless meaning already known • Use icon design tools to experiment
ISO Standard’s Classification • Interactive icons • Mediate user interaction with software application • Non-interactive icons • Status indicators
Icons Classification(ISO/IEC Based) Icons Interactive Non-interactive Status Indicator Object Pointer Control Tool Selection Text Graphics Cut/copy Spellcheck Up/down arrows Fill Eraser Pencil Hourglass ‘LEDs’ Device Data Container Folder In-basket Document Chart S’sheet Printer Telephone
IBM Common User Access Workplace Environment (1988):3 Categories of Icons • Container • Data • Device
Lecture Review • Definition • Advantages and disadvantages • Factors affecting meaningfulness • Form and function • Design guidance • Classification