Fix affordance entry.

[vigliensoni]

@aliciailiesiu, please correct the citations in your entry. For instance, if you cite Gibson (1977, 1979), there should be two bibliographic entries: one for the 1977 publication and another for the 1979 publication.

CART210-glossary/keywords/affordance.md

Line 3 in fd84ade

Gibson (1977, 1979) coined the term “affordance” to describe what the environment “offers the individual, what it provides or furnishes, either for good or ill” .Affordances can be viewed as animal-relative properties of the environment. They correspond to the action possibilities offered to an animal by the environment with reference to the individual’s action capabilities. For example, a leaf provides support for a wasp but not for a dog. Here, the support-ability of the leaf is an affordance for the wasp. Affordances can vary not only between species but also between the individuals of the same species. A 30-cm stair is climb-able for an adult but not for a child. In sum, affordances are neither objective nor subjective, but both. They are objective because they exist independently of the act of perception. But, they are also subjective because the frame of reference is the individual’s action capabilities.

Additionally, splitting your one-paragraph entry into three or four shorter paragraphs would enhance clarity. Each paragraph should cover a different aspect of the keyword.