To ensure the success of the near future home-service robots, it is essential to develop an affordable and effective instruction mechanism that is well fitted both to the characteristics of the tasks the robots will perform and the work environment where they will operate. As an early exploration of this line of studies, this paper explores a situation where human operators direct a robot to a particular place within a limited workspace using a handheld device. The three experiments revealed that a successful map representation would have significant benefits for the human operator's awareness of both the task and the work environment. As a consequence, several design guidelines for the map representation were empirically attained. (c) 2007 Elsevier B.V. All rights reserved.