1. a temporary readiness to perceive certain objects or events rather than others. For example, a person driving a car has a perceptual set to identify anything in the car or on the road that might affect his or her safety. See selective perception.

2. a schema or frame that influences the way in which a person perceives objects, events, or people. For example, an on-duty police officer and a painter might regard a crowded street scene with very different perceptual sets.