be picked up, based on his effectivities. This view is consistent with Norman's (1988) theory of "perceived affordances," which emphasizes the agent's perception of an object's utility as opposed to focusing on the object itself.

An interesting question is the relationship between affordances and mental representations as set forth in a more cognitivist perspective. While Greeno (1998) argues that attunements to affordances are superior to constructs such as schemata and mental models,