Our perception is Biased Johnson Chapter 1 Our perception is Biased

Facts about Human Perception & Cognition (Overview of Johnson’s Book) We perceive what we expect Our vision is optimized to see structure We seek and use visual structure Reading is unnatural Our color vision is limited Our peripheral vision is poor

Facts about Human Perception & Cognition (cont.) Our attention is limited; Our memory is imperfect Limits on attention shape our thought & action Recognition is easy; recall is hard Learning from experience & performing learned actions are easy; problem-solving & calculation are hard Many factors affect learning We have real-time requirements

We Perceive What We Expect Our perception is biased by: Our experience The context Our goals

We Perceive What We Expect!

Is the army headed west or east?

We tend not to notice things that are unrelated to our goal

We Perceive What We Expect Our perception is biased by: Our experience The context Our goals

Context Fold napkins. Polish silverware. Wash dishes.

Context French napkins. Polish silverware. German Dishes

We Perceive What We Expect Our perception is biased by: Our experience The context Our goals Missing Context

Necker Cube

We Perceive What We Expect Our perception is biased by: Our experience The context Our goals Inconsistent Context

Maurits Cornelis Escher

We Perceive What We Expect Our perception is biased by: Our experience The context Our goals

What courses are taught by the Computer Science Department?

Design Implications Avoid ambiguity Be consistent Understand the goals

New Vaccine Contains Rabies Avoid Ambiguity New Vaccine Contains Rabies

Design Implications Avoid ambiguity Be consistent Understand the goals

Which design is best?

Be Consistent

Design Implications Avoid ambiguity Be consistent Understand the goals