This document discusses J.J. Gibson's concept of affordances. Some key points: 1. Gibson defined affordances as all that environments offer animals for good or ill. This refers both to the environment and animal. 2. He founded the school of ecological psychology, arguing that perception is direct and animals stand in relation to their environment. 3. Affordances include things like nutrition, dying, drive-on surfaces, stove controls, and cognitive affordances provided by culture. Later authors expanded on affordances based on body size.

1. A
Anton Flügge, Hannes Schulz
University of Osnabrück, Department of Cognitive Science
December 21st 2005

2. O
1 G   C  A
2 D T  A
3 L D A
4 M. A  A
5 A

3. O
1 G   C  A
2 D T  A
3 L D A
4 M. A  A
5 A

4. Gibson’s Concept Types Later Definitions Aspects Application
J J G
1904, McConnelsville, OH
1979, Ithaca, NY
Ph.D. Psychology, Princeton, 1928
Worked at Cornell University,
Ithaca, NY
Main contribution: The Perception
of the Visual World (1950)
Claims perception is direct
Invented influential term
“Affordance”
Founded School of Ecological
Psychology
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5. Gibson’s Concept Types Later Definitions Aspects Application
E P
E P
“It’s not what is inside the head
that is important, it’s what the
head is inside of”
Animals stand in a relation
to the environment
To explain behaviours it is
necessary to study the
environment in which
behaviours take place
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6. Gibson’s Concept Types Later Definitions Aspects Application
D P
D P
Perception is gathering
information from meaning-laden
environment without performing
inferences on the sensations
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7. Gibson’s Concept Types Later Definitions Aspects Application
G’ A-D
D (A)
The affordances of the environment are what it offers the animal,
what it provides or furnishes, either for good or ill. The verb to
afford is found in the dictionary, but the noun affordance is not. I
have made it up. I mean by it something that refers to both, the
environment and the animal in a way that no existing term does.
Animal Environment
Nutrition
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8. O
1 G   C  A
2 D T  A
3 L D A
4 M. A  A
5 A

9. Gibson’s Concept Types Later Definitions Aspects Application
E: B A
Nutrition Dying
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10. Gibson’s Concept Types Later Definitions Aspects Application
E: P A
Drive-on Affordance
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11. Gibson’s Concept Types Later Definitions Aspects Application
E: P A
Stove-Top-Control
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12. Gibson’s Concept Types Later Definitions Aspects Application
E: C A
Cognitive Affordances are provided by cultural conventions
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13. Gibson’s Concept Types Later Definitions Aspects Application
E: M A
Knowledge (Semantic Affordance)
Mixed Affordance
Ties (Physical Affordance)
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14. O
1 G   C  A
2 D T  A
3 L D A
4 M. A  A
5 A

15. Gibson’s Concept Types Later Definitions Aspects Application
A  B S
Warren (1984): Used “affordance” as ratio between size of
body-parts and environment
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16. Gibson’s Concept Types Later Definitions Aspects Application
D
D (D)
Tendency to any action or state resulting from natural constitution
Dispositions are always actualized if certain circumstances occur
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17. Gibson’s Concept Types Later Definitions Aspects Application
T’ (1992) F
D (A)
p is Affordance ⇔ ∃Wpq : Wpq = j (Xp , Zq ) (1)
Environment X Animal Z
p Disposition of the p q
Environment
q Disposition of the Animal
X Environment j
Z Animal
j Juxtaposition
Wpq
Wpq Entity with (new)
r
property r
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18. Gibson’s Concept Types Later Definitions Aspects Application
S’ (2003) C
1 Affordances should describe what can be
done, not what has to be done.
2 In any situation many actions are
possible, most aren’t actualized.
3 Dispositions must be actualized in the
right circumstances (Turvey’s def), but j
filters them: Inconsistent.
4 Based on Turvey the property r cannot be
directly perceived, it must be inferred
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19. Gibson’s Concept Types Later Definitions Aspects Application
S’ (2003) D
D (A)
An Affordance r is an emergent property of the
animal-environment system Wpa = (Xp , Za ).
Environment X Animal Z
p a
p Disposition of the
Environment
a Ability of the Animal
Emergence
X Environment
Z Animal
Wpa Entity with emergent Wpa
property r r
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20. Gibson’s Concept Types Later Definitions Aspects Application
C (2003)
N U
Affordances are relations, not properties of entities
Relation TallerThan(Averell, Joe)
The relation is not inherent in either
of the objects but depends on both
of them
The relation is not an extra “thing”,
yet it exists and is perceivable
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21. Gibson’s Concept Types Later Definitions Aspects Application
C’ A D
D
An Affordance is a relation between a feature f of the environment
and an ability a of the animal: Affords-Φ(f , a)
Φ Behavior
Affords-Φ Environment X Animal Z
Relation/Affordance f a
f Feature of Environment
a Ability of Animal
Affords-Φ
X Environment
Z Animal
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22. O
1 G   C  A
2 D T  A
3 L D A
4 M. A  A
5 A

23. Gibson’s Concept Types Later Definitions Aspects Application
A  E
Reed (1996): Affordances are offered by Environment
Affordances exist independently of animals
Affordances exert selection pressure during evolution
Observed complementarity is an epiphenomenon
23 / 26

24. Gibson’s Concept Types Later Definitions Aspects Application
A R  A E
According to previous
definitions a matching
animal must exist for
something to be called
“affordance”.
Analogous to Dennett
(1998): Female hippos
depend for loveliness on
potential observer,
suspiciousness needs an
actual observer
Affordances are “lovely”,
not “suspicious”.
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25. Gibson’s Concept Types Later Definitions Aspects Application
T M P
Indirect View of Perception Direct Perception of Affordances
Direct View of Perception
Affordances can be a solution to
the problem how our minds can
be private when we assume
perception to be direct.
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26. Gibson’s Concept Types Later Definitions Aspects Application
E
D (E)
An Event is a change in the layout of affordances (Chemero 2000)
26 / 26

27. Gibson’s Concept Types Later Definitions Aspects Application
N
D (N)
A niche is a set of affordances (Gibson, 1979)
Gibson Bruce
Environment Housing
Nutrition
27 / 26

28. O
1 G   C  A
2 D T  A
3 L D A
4 M. A  A
5 A

29. Gibson’s Concept Types Later Definitions Aspects Application
A: H C I
User interface affordances in a planning representation
(Amant 1999)
U  A C
Affordances are used to
determine the costs for
execution of operators
generation of operators
Affordances used to model
usability of user interfaces
Allows “search” for optimal
design in problem space
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30. Gibson’s Concept Types Later Definitions Aspects Application
A: S D
Affordance Theory for Improving the Rapid Generation,
Composability, and Reusability of Synthetic Agents and Objects
(Cornwell 2003)
I am
attackable U  A C
Objects in Env’t tell agents
what they are useful for
Easy adding of new agents
Enhanced reusablitiy
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31. Gibson’s Concept Types Later Definitions Aspects Application
S
“Affordance” is a term Even without a consensous
invented by James J. Gibson various fields of research
have been stimulated
The concept is intuitively
appealing
There is an ongoing debate
about a formal definition
31 / 26