Gibson's Affordances - Notes

James J. Gibson
The Theory of Affordances

The replicant, Zhora, with an artificial snake in Blade Runner.

"Of course it's not real. Do you think I'd be working in a place like this if I could afford a real snake? " A-Harrison-Ford When thinking about electronic sensors we are now dealing with an "alien" perception of affordances. Therefore it is necessary to define what afforances your work is first dependent on, and then secondarily how those affordances are perceived through electrical "eyes". Since electricity has no biological (anything) optics, the sensors included in a circuitboard's total logic begin defining what affordances the object has available to it to perceive. Think about what is divulged to the software logic and hardware design, and what is concealed. How do you handle misperception? Is it embraced, or edited?

• Value and meaning of observable affordances are secondary to the primary affordance of observation.
• "What is meant by an affordance? ...the affordance of anything is a specific combination of properties of its substance and its surface taken with reference to an animal."
• "...affordances may be more easily perceived by an animal than the properties in isolation, for the invariant combination of properties is 'meaningful' whereas any single property is not."
• "What other persons afford, for man, comprise the whole realm of social significance. "
• Environment affords postures, food, water, shelter. The qualities of these affordances combine to form a niche, into which animals "fit" themselves.
• "An affordance is not what we call a 'subjective' quality of a thing." --it does not depend on the animal, observer..."But neither is it what we call an "objective" property of a thing if by that we mean a physical  object has no reference to any animal. An affordance cuts across  the dichotomy of subjective-objective and helps us to understand its inadequacy."
• "The information for imminence of collision is a high rate of symmetrical outflow of part of the ambient optic array, the approach to the maximum possible visual solid angle which specifies zero distance. This can be describe as "looming"."
• "One of the rules of ecological optics is that at any fixed point of observation some parts of the environment are projected or revealed and the remaining parts are unprojected or concealed. "
• "Behavior affords behavior..."
• Affordances can be both positive and negative, but do not subjectively correlate with pleasure or displeasure.
• "When an observer perceives edibility he perceives it in relation to his mouth and teeth and digestive system..."
• ecological optics
• "The very possibility of perceiving entails, of course, the possibility of misperceiving."
• "When Koffka asserted that "each thing says what it is" he neglected to mention that it may lie."