By Taivan, C.; Jos\'e, R.; Silva, B.
Computer Systems Science and Engineering
Digital display technology is facing considerable progress and large screens are increasingly pervasive in our public environment. Most display systems exist as non-interactive units, broadcasting multimedia content, such as text, images and videos and work under tight control of their owners. These installations usually do not take much consideration for the audience, as information is pushed regardless of viewers’ interests. Although the pervasiveness of these displays has increased in the last decade, they do not provide considerable added value for people’s lives. This means that public displays have not yet managed to integrate the emerging eco-system of services and devices that constitute a ubiquitous computing infrastructure. Open Display Networks are an emergent paradigm that considers the possibility of opening the currently closed networks and invite audience into new levels of engagement through the usage of sensing and interaction capabilities. It also entails the idea that display owners will benefit from opening their display networks for third party software applications and multimedia content. This originates multi-application displays that can engage viewers in a wide range of usage scenarios similarly to what happened with smartphones. This research addresses the conceptual and technical challenges for the concretization of the applications for interactive public displays. Our work contributes with the fundamental understanding of what a display application might be and how it should be designed, developed and used as part of multi-application display experiences. We came out with a set of application design principles and characteristics that may guide application creators in the design space of multi-application displays. This thesis also contributes to the understanding of the implications that display applications might have on the use of Web technologies as an appropriate technological framework for the creation of this type of applications. We identified a set of Web development specificities and insights that help third-party developers to understand in what ways a display application is different from its desktop or mobile counterparts. The new findings developed as part of this thesis are expected to have an impact on the emergence of potential web-based application models and related application eco-systems. This in turn would determine the deployment of multi-application display systems that would embed many use cases and therefore increase benefits for all the parties involved.