This document discusses how groups and situational factors influence consumer decision making. It explains that consumers are influenced by their mood, whether they are alone or with others, time constraints, how they will use a product, and their self-image. Situational factors like physical environment, shopping orientation, usage of the product, and time pressures all affect purchase decisions. Reference groups like family, friends, and aspirational figures also influence consumers through normative pressures, comparative influence, and the desire for acceptance.