Abstract. This paper discusses the provision of ubiquitous services for desktop and handheld interfaces. The focus of the paper is on the interactive agenda offered by INTRIGUE, a tourist information server which assists the user in the organization of a tour by providing personalized recommendations of tourist attractions and helping the user to schedule her itinerary. The interactive agenda can be accessed both remotely, by interacting with the central server, and locally to the user's device.
BackgroundWith the current expansion of wireless communications, several Web-based services have been extended to the mobile phone market, with special attention to contextawareness and to the adaptation of the user interface to the peculiarities of the various handset devices. However, only very basic, "real-time" services, such as the consultation of stock quotes, are accessed by mobile phone users, because wireless connections are extremely expensive. In contrast, the applications that can be executed locally to the device, such as music and games, are appreciated by a broader customer base. Although the situation might change in the future, at the current stage applications should rely on wireless network connections for the tasks that really need a remote connection [1].In our recent research, we have addressed the design of system architectures for the development of services accessible both from desktop environments and handset devices, via remote connections to central servers, or local execution of tasks within the devices themselves. In these applications, persistent interaction contexts have to be managed to support the synchronization of the user's activities when switching from one device to the other [2]. We experimented our ideas with INTRIGUE (INteractive TouRist Information GUidE), a prototype information service presenting tourist information on Web browsers and WAP phones. This paper describes INTRIGUE's interactive agenda, which supports the tour scheduling by generating optimized itineraries on the basis of the user's temporal constraints, the attractions' opening times and their location. In this application, the persistent interaction context is represented by the user's itinerary, which can be consulted and modified during different sessions. The interactive agenda is downloadable and can run both in remote modality, by interacting with £ This paper has been published in LNCS n. 2347, Springer Verlag.