Improving Reachability and Navigability in Recommender Systems

In this paper, we investigate recommender systems from a network perspective and investigate recommendation networks, where nodes are items (e.g., movies) and edges are constructed from top-N recommendations (e.g., related movies). In particular, we focus on evaluating the reachability and navigability of recommendation networks and investigate the following questions: (i) How well do recommendation networks support navigation and exploratory search? (ii) What is the influence of parameters, in particular different recommendation algorithms and the number of recommendations shown, on reachability and navigability? and (iii) How can reachability and navigability be improved in these networks? We tackle these questions by first evaluating the reachability of recommendation networks by investigating their structural properties. Second, we evaluate navigability by simulating three different models of information seeking scenarios. We find that with standard algorithms, recommender systems are not well suited to navigation and exploration and propose methods to modify recommendations to improve this. Our work extends from one-click-based evaluations of recommender systems towards multi-click analysis (i.e., sequences of dependent clicks) and presents a general, comprehensive approach to evaluating navigability of arbitrary recommendation networks

Perceptual impact of environmental factors in sighted and visually impaired individuals

To a visually impaired individual the physical world presents many challenges. For a person with impaired sight, wayfinding through a complex environment is fraught with dangers, both actual and imagined. The current generation of mobility aids have the possibility of addressing a broad range of physical issues through technological solutions. The perception of difficulty however, can mean that many visually impaired individuals are fearful or uncomfortable about independent mobility or travel. In this context it becomes necessary to discover exactly what environments, environmental factors or items constitute a ‘perception of difficulty’ in the individuals mental landscape and may trigger a negative response before they interact with the physical environment. This paper reports on research, which sought to ascertain what levels of perceptual difficulties specific environments and factors presented to individuals. The research was conducted with both visually impaired and sighted groups and compared differences and similarities in perceptual difficulty between these two groups

Users' trust in information resources in the Web environment: a status report

This study has three aims; to provide an overview of the ways in which trust is either assessed or asserted in relation to the use and provision of resources in the Web environment for research and learning; to assess what solutions might be worth further investigation and whether establishing ways to assert trust in academic information resources could assist the development of information literacy; to help increase understanding of how perceptions of trust influence the behaviour of information users

Psychological aspects of information seeking on the Internet

Two studies are presented that investigate information seeking behaviour on the Internet. In Study One, soccer fans’ information seeking on the World Wide Web (WWW) is investigated. In Study Two, access rates to a cancer information website are analysed. It is tentatively argued that there is a tendency for people to access information more commonly avoided in ‘real life’, although in the case of football fans, the tendency to ‘bask in reflected glory’ remains when online, while cutting off reflected failure is minimised. Implications for understanding and researching psychological processes of web browsing behaviour are discussed

Virtual reality and its role in removing the barriers that turn cognitive impairments into intellectual disability

Early expectations of the contribution that virtual reality (VR) could make to education far exceeded actual applications. This was largely due to the initial immaturity of the technology and a lack of evidence base on which to base design and utilisation. While the early developments in computer based learning largely concentrated on mainstream education, leaving those with special needs behind, the potential of VR as an educational tool was exploited for those with intellectual disabilities right from the start. This paper describes the empirical evidence that has contributed to the development of educational virtual reality for those with intellectual disabilities: studies on transfer of learning from the virtual to the real world; how teachers might support those using VR; the design of virtual environments and what input/control devices best facilitate use of desktop VR. Future developments and ethical issues are also considered

Lecture III: There are maps and there are maps – motives, markets and users

This is the third of three lectures given on 5,6 and 8 March 2007 as the Sandars lectures for that year at Cambridge University Library. The text is as read at the time, but includes some later revisions and citations to works used within the text. The slides shown are listed in a separate document.Cambridge University Library, Sandars Readership in Bibliograph

EGO: a personalised multimedia management tool

The problems of Content-Based Image Retrieval (CBIR) sys- tems can be attributed to the semantic gap between the low-level data representation and the high-level concepts the user associates with images, on the one hand, and the time-varying and often vague nature of the underlying information need, on the other. These problems can be addressed by improving the interaction between the user and the system. In this paper, we sketch the development of CBIR interfaces, and introduce our view on how to solve some of the problems of the studied interfaces. To address the semantic gap and long-term multifaceted information needs, we propose a "retrieval in context" system. EGO is a tool for the management of image collections, supporting the user through personalisation and adaptation. We will describe how it learns from the user's personal organisation, allowing it to recommend relevant images to the user. The recommendation algorithm is detailed, which is based on relevance feedback techniques