1. an approach to environmental psychology that emphasizes the continuing process of interaction between a person and his or her physical and social environment. This process is characterized as an ongoing series of “transactions” in which the person’s behaviors are modified by environmental factors and vice versa.

2. an approach to perception that emphasizes the interaction of people and their environments. Rather than being mere passive observers, people draw on past experiences to form perceptions of present situations and even of novel stimuli. —transactionalist adj., n.