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Introduction toDesign Principles

Based on Don Norman’s book“The Design of Everyday Things”

Michael Rawlins, Director, Interaction Design & Strategy

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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

all are as people…Michael Rawlins

Interaction Designer

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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 problematicdesigns.

• Established Design Principles as a framework fordiscussing and thinking about interaction problems.

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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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Visibility• Can you see the state of the device

& possible actions?• Are the controls positioned in a

manner where they can easily befound and used?

• Problems arise when users can’t seehow to use the device.

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Poor Visibility• Which controls are ambiguous?• How does this device turn off?• Which controls have meanings that

are unclear?.

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Better Visibility

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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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Affordance• Perceived and actual properties of an object that provides

clues to its operation.

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Poor Affordance?• What’s clickable below?

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Better Affordance…• Why do these examples have

better visual affordance?

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Mapping• The relationship between controls and

their effect.• Do these devices work with each

other?

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Mapping• Problematic examples (what’s good and what’s bad?)

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Constraints• Restricting the kind of actions a user

can take.

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Constraints• How is the users attention

directed to notice thesystem constraints?

• What other constraintsshould the user notice?

• How does users safetyimpact the design of thisgas pump?

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Consistency• Design interfaces to have

similar operations & usesimilar elements for achievinglike tasks.

• Similarity increaseslearnability.

• Design to aid prior systemknowledge - and aid the usersshort and long-term memory.

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ConsistencyFour 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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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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Further Reading…

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Thank You…

Credit to David Gelb