This document discusses how technology can influence human behavior. It begins by reviewing McLuhan's view that technology extends human senses. It then discusses how technologies have certain affordances and qualities that make actions easier. Persuasive technologies are designed to influence behavior using the EAST framework of making things Easy, Attractive, Social and Timely. The document explains how technologies can act as extensions that amplify existing human effects through increased uncertainty online or anxiety with multiple audiences. It also discusses how technologies can shape behavior through choice architecture, defaults, constraints, rewards and by applying social rules to interactions with computers.