Location-based decision support for user groups

The ongoing progression of mobile communication devices, in particular with respect to positioning capabilities, has enabled the development of a new generation of location-based services (LBS). One of the most important aspects of current research on LBS is personalisation but it has been treated primarily for individual users. This article presents a first step towards personalised LBS that support user groups in their everyday decision-making, such as deciding where and when to meet for a common activity. The principles behind location-based group decision processes are outlined and a formal model for supporting such processes using methods of multi-criteria decision-making, time geography and similarity measurement is defined. This model is then implemented in the LBS prototype mediatrix. The prototype is used for simulating a location-based decision process aimed at finding an optimal restaurant for a user group in a city.