The question of how much speakers consider their addressees perspectives is a topic of debate. In these experiments, I examine this question in a novel way by observing overhearer reactions to the conversational constraints set on the conversations interlocutors. I compare how the overhearers to monologues and dialogues understand directions. These experiments were conducted in a computer-mediated environment, but are expected to have a degree of generalizability to face-to-face communication as well as implications for human-computer interaction. Keywords: grounding in communication; perspective-taking; in-group and out-group differences; audience design; overhearer effects.