Σημασιολογικά εμπλουτισμένες διεπαφές πλοήγησης στον παγκόσμιο ιστό

Abstract

Browsing in the World Wide Web (WWW) for disabled users poses a series of problems. This thesis presents the idea of Browsing Shortcuts (BS) as a way of dealing with those problems. In particular, it specializes in the problems that Visually Impaired (VI) people confront when browsing the WWW. After a thorough analysis of the problems of VI users, it is obvious that the main cause for them is that today web pages carry a great deal of visual meta-information for sighted users, which is not communicated to VI users. BSs is a mechanism that compensates disabled users for the information they lose while browsing. For VI users in particular, BS allow them to recognize easily content areas and other functional elements that exist in the web page such as a newspaper article, a menu, a search form etc. in addition, BSs also provide users with the necessary functionality to transfer them quickly to the each of the elements in order to use them appropriately. The technological framework that supports the implementation of the BSs idea is based on Semantic Web (SW) technologies. This way the implementation of BSs ensures its extensibility, scalability and independence from the current web content production community. The implementation of BS is supported by a community of people that are motivated to participate in their solution (eg. family, friends, teacher of VI persons), and are separated into groups with specific roles. Therefore it stands in solid foundation. From the evaluation process, through experiments, a series of results led to specific conclusions about the application of the BSs mechanism. VI users using the BSs made less effort (less keystrokes) and read quicker the web pages compared to the browsing without the BSs. The latter, also led to the increase of web page visits during an information seeking process and in the increase of information read by the users during it. Combining these findings with the fact that users read web pages more carefully when using the BSs, than without them, and the change of strategy during their browsing within web pages, we understand that apart from the quantity of information, the quality of the information retrieved, during an information seeking task, is also increased. Apart from the basic version of the BSs, two more versions of the idea were also examined in order to find whether they can improve even more the browsing with BSs. In the respective experiments the results show that, in order for Spatially Enriched BSs to be used effectively users need a bigger familiarization period with the spatial information. On the contrary, this is not the case with the use of Adaptive BSs which adapt the BSs list according to users? needs and seem to perform with quite positive results.