1. CEN3722 Human Computer Interaction Interface Metaphors and Conceptual Models
Dr. Ron Eaglin

2. Objectives Define and describe how metaphors are used in design
Verbal metaphor
Virtual metaphor
Composite metaphor
Define and provide examples of Conceptual Models
Design model
User’s model
System image

3. Metaphor

4. Metaphors Used to control complexity
Interface actions or tasks mapped to already understood concepts
User prior experience and knowledge to help with the novel or unfamiliar
Establish user expectations
Allow predictions of system behavior

5. Metaphor Example - Desktop
Clipboard
Recycle bin
Trash
File cabinet
Calendar
Clock
Messages
Note the mismatch of Windows 8 to the metaphor of the desktop as compared to Mac

6. Types of Metaphors
Verbal metaphor – comparing previous (old) to new technology.
Example: Word processor vs. typewriter
Virtual metaphor – interface elements with metaphor
Example: Desktop adds mouse clicks= selection, drag/drop = move
Composite metaphor – add new features to metaphor
Example: Add menus to desktop metaphor (new feature)
Virtual metaphors provide one:one relationship in metaphor, where composite adds elements that do not exist in base system

7. Conceptual Models How systems are understood by different people
User conceptualize the system
Designers conceptualize the system
These should be consistent
Interfaces communicate the conceptual model
Should not need documentation
Things should be visible

17. Design Model User Model
User gets model from experience and usage
If the models match – ease of use
If not user makes mistakes – rejects UI

18. Summary Define and describe metaphors and use in design
Verbal metaphor, virtual interface metaphor, composite metaphor
Define and give examples of conceptual models
Design model, user model, system image