Insights into human visual attention have benefited many areas of computing, but perhaps most significantly visualisation and UI design [3]. With the proliferation of mobile devices capable of supporting significantly complex applications on small screens, demands on mobile UI design and the user's visual system are becoming greater. In this paper, we report results from an empirical study of human visual attention, specifically the Change Blindness phenomenon, on handheld mobile devices and its impact on mobile UI design. It is arguable that due to the small size of the screen - unlike a typical computer monitor - a greater visual coverage of the mobile device is possible, and that these phenomena may occur less frequently during the use of the device, or even that they may not occur at all. Our study shows otherwise.

The increasing power and ubiquity of mobile phones mean that a visitor to a city now carries with them a device capable of giving quite detailed guiding and routing information. Whilst there has been a lot of studies of text and map based guiding applications for mobile devices, in this paper we want to propose and give an initial exploratory study of a guiding system that utilises photographs. These photographs are not explicitly taken with the intention of using them subsequently for giving route directions; rather they are extracted from existing geo-tagged photo collections from mobile phones. A user of our system sees a route description as text and a map that refers to a series of photographs. The main contribution of this paper is in demonstrating this concept and testing it in an exploratory between-subjects experiment. The experiment shows that presenting the right photographs certainly can help with particular types of routing instruction for users not familiar with an area. For example, in unusual situation where the user has to walk through a specific gate or path, photographs provide information and reassurance about the navigation decision.

The central goal in Distributed Virtual Environments (DVEs) is to provide an experience of the shared world that is perceptually plausible for the immersed user. This has to be achieved in the face of network issues such as bandwidth limitations and latencies which make total synchronism impossible. Techniques have been devised to help; some optimise network use by limiting what is transmitted, others try to disguise the effects of network 'glitches' at the user's client machine - for example smoothing policies. To date such techniques tend to be system-based rather than user-oriented. Yet there is an active body of psychological research, for example in visual attention, which has successfully been employed by the graphics community to yield better perceived results for a given resource. Immersive DVEs are even more critically dependent upon the users' perceived experience. We may expect therefore that such 'psychologically' oriented approaches have even more to offer here. In this paper a visual attention model which exploits the peculiarities of the human visual system is presented. It is based on previous work, and on a series of carefully designed experiments which are used to guide the implementation of the model and to design architectures for DVEs. The proposed architectures are then tested using different DVE experimental applications, which include a highly populated virtual city. The results demonstrate that the characteristics of the human visual system can be exploited to improve network usage and generate a more perceptually plausible environment in the face of incomplete synchronisation.