We have implemented and tested a PDA-based system that gives a shopper directions through a shopping mall on the basis of (a) the types of products that the shopper has expressed an interest in, (b) the shopper's current location, and (c) the purchases that the shopper has made so far. The system uses decision-theoretic planning to compute a policy that optimizes the expected utility of a shopper's walk through the shopping mall, taking into account uncertainty about (a) whether the shopper

more »

... actually find a suitable product in a given location and (b) the time required for each purchase. To assess the acceptability of this approach to potential users, on two floors of a building we constructed a mock-up of a shopping mall with 15 stores. Each of 20 subjects in our study shopped twice in the mall, once using our system and once using a paper map. The subjects completed their tasks significantly more effectively using the PDA-based shopping guide, and they showed a clear preference for it. They also yielded numerous specific ideas about the conditions under which the guide will be useful and about ways of increasing its usability. 4 To facilitate exposition, we will use the term products even when what is really meant is products, services, and combinations of both. The symbol¨will denote the system under discussion, while © will refer to a user of that system. 5 A system may provide navigation support to guide © from her current location to the exact nearby place where she can obtain the recommended product; but the current location is still treated as given. 9 This technical solution is currently being implemented by the company that supplied the beacons. But as this solution does not overcome the problem if © points interface at the floor, other technologies, such as Bluetooth, might be employed to indicate the presence of a transmitter regardless of the position of the PDA.