This document introduces design principles based on Don Norman's book "The Design of Everyday Things". It discusses Norman's work in user-centered design and establishing principles like visibility, feedback, affordance, mapping, constraints, and consistency as a framework for analyzing interaction problems. Each principle is defined and examples are provided to illustrate both proper and poor implementations. The document concludes that design principles are validated by usability methods that evaluate learnability, efficiency, memorability, errors, and satisfaction.

1. Introduction to
Design Principles
Based on Don Norman’s book
“The Design of Everyday Things”
Michael Rawlins, Director, Interaction Design & Strategy
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2. Why me?
• I’m very curious…
• I understand multiple disciplines.
• Bad user experiences bother me.
• I have passion for solving problems.
• I’m intrigued by how different we
Michael Rawlins
Interaction Designer all are as people…
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3. About Don Norman
• A cognitive scientist and engineer who pioneered concepts
related to user centered design.
• Worked at Apple & HP. Now @ NNG (http://www.nngroup.com)
• Examines everyday things as examples of problematic
designs.
• Established Design Principles as a framework for
discussing and thinking about interaction problems.
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4. Design Principles
• Visibility - can I see the interaction?
• Feedback - what’s the object or device doing right now?
• Affordance - how do I use it?
• Mapping - where am I & where can I go?
• Constraints - why can’t I do that?
• Consistency - is this familiar?
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5. Visibility
• Can you see the state of the device
& possible actions?
• Are the controls positioned in a
manner where they can easily be
found and used?
• Problems arise when users can’t see
how to use the device.
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6. Poor Visibility
• Which controls are ambiguous?
• How does this device turn off?
• Which controls have meanings that
are unclear?.
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7. Better Visibility
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8. Feedback
• What is the device doing right now?
• What action is being performed?
Feedback is often multi-sensory
(an audible click and a visual clue of interaction)
How does this work?
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9. Affordance
• Perceived and actual properties of an object that provides
clues to its operation.
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10. Poor Affordance?
• What’s clickable below?
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11. Better Affordance…
• Why do these examples have
better visual affordance?
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12. Mapping
• The relationship between controls and
their effect.
• Do these devices work with each
other?
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13. Mapping
• Problematic examples (what’s good and what’s bad?)
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14. Constraints
• Restricting the kind of actions a user
can take.
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15. Constraints
• How is the users attention
directed to notice the
system constraints?
• What other constraints
should the user notice?
• How does users safety
impact the design of this
gas pump?
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16. Consistency
• Design interfaces to have
similar operations & use
similar elements for achieving
like tasks.
• Similarity increases
learnability.
• Design to aid prior system
knowledge - and aid the users
short and long-term memory.
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17. Consistency
Four types of consistency:
• Aesthetic - style & appearance is repeated to enhance
recognition.
• Functional - meaning and action is consistent to reinforce
learnability and understanding.
• Internal - indicates a system is planned & well thought out
(cultivates trust and user orientation).
• External - establishing an ecosystem & consistency with
other elements in the environment.
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18. Conclusion…
Design Principles are validated by usability methods:
• Learnability - how easy is it to perform basic tasks upon the
users first encounter with the device or interface.
• Efficiency - once the users are familiar with the interface, how
quickly and effectively can they perform tasks.
• Memorability - when users return after not having used the
system, how quickly can they reestablish proficiency?
• Errors - how many errors do users make? How severe are the
errors? Can the users easily recover from errors?
• Satisfaction - how pleasant and effective is the user experience?
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19. Further Reading…
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20. Thank You…
Credit to David Gelb 20