The ubiquitous environment enables us to build systems that provide individual users with personalized navigation services in cities. In developing such a system, it is necessary to estimate the influence and the movement of its users and to get feedback. However, it is difficult to perform tests on such a system given the large number of human subjects involved and its scale, which matches that of a major city. One possible solution is proposed herein, the augmented experiment; it combines a multiagent simulation with a small-scale experiment performed with human subjects. In the experiment, the movements of agents that simulate users are shown to human subjects in order to give them the impression that the environment is populated with a large number of users. In this research, we build a evacuation guide system based on GPS-capable cellular phones and perform an augmented experiment wherein human subjects and evacuee agents are directed while the status of the simulation is passed to the human subjects. Interviews of the human subjects confirmed that the augmented experiment successfully gave the impression that a large number of users were present.