ABSTRACT
The work group on perception and action was concerned with those events that Gibson called "encounters ," that is , events that involve an organism's perceptual-motor activity. Like inanimate events such as rotation or breaking , encounters may be desc ribed in terms of structural and transformational invariants and a temporal period over which the event transpires (see Warren & Shaw , this volume). However , the work group was concerned less with how actions are specified to an onlooker than with how actions are appropriately selected (the detection of affordances) and tailored to local conditions (the perceptual control of activity) by the participant . As Lee put it, the problem is one of discove ring perceptual information about andfor the act.
