Games are fundamentally a social activity. The effects of this foundation can be felt at every level - from the social negotiation of rules, through cooperation and collaboration between players during the game, to the effects of relationships and social status on play. Social effects can change the way the game is played, but the mechanics of games can also affect the patterns of social behaviours of the players. The arrangement of game mechanics and interfaces together defines a ``social architecture". This architecture is not limited to directly social mechanics such as trading and messaging - the game design itself has a holistic effect on social activity. This dissertation frames games around these social aspects, and focuses on analysis of the patterns that emerge from these playful interactions. Firstly, a model is defined to understand games based on the social effects of play, and these effects explored based on the varying impact they have on the play experience. Mischief and deviance is also investigated as forces that challenge these social effects in and around games. Based on interaction data gathered from server logs of experimental social games, social network analysis is used as a tool to uncover the macroscopic social architectures formed by each design. This allows the use of quantitative methods to understand the nature of the relationship between game design and the social patterns that emerge around games in play. Key findings confirm that social activity follows a heavy-tailed distribution - a small number of ``hardcore" players are responsible for a disproportionately large number of interactions in the community of the game. Further than this, the connections between active hardcore and the rest of the player base show that without the hardcore users, the community of games as ``small worlds" would collapse, with large numbers of players being separated from the society within a game. The emergence of grouping behaviour is investigated based on the effect of social feedback. Following findings of social psychology in non-game environments, evidence is provided that highlights the effect of socio-contextual feedback on players forming strongly bound tribal groups within games. The communities formed through the play of games can be described in terms of network graphs - webs of interactions flowing around a network of players. Social network analyses of social games show the emergence of patterns of reciprocity, clustering and tribal behaviours among the players. The evidence also shows that the collections of game mechanics, or social architectures, of games have a predictable effect on the wider social patterns of the players. As such, this suggests games can be specifically engineered for social effects based on changes in the patterns of interactions, and issues around mechanical or interface elements can be identified based on anomalies observed in the network graph of player interactions. Together, this dissertation provides a link between the theoretical ideas around social play to the measurable effects of social behaviours of players within games. It proves that game designs, as mechanical systems, have a demonstrable effect on the social patterns of play, and that these patterns can be examined and used to engineer better game designs for the benefit of social experience.

Current human-aware navigation approaches use a predominantly metric representation of the interaction which makes them susceptible to changes in the environment. In order to accomplish reliable navigation in ever-changing human populated environments, the presented work aims to abstract from the underlying metric representation by using Qualitative Spatial Relations (QSR), namely the Qualitative Trajectory Calculus (QTC), for Human-Robot Spatial Interaction (HRSI). So far, this form of representing HRSI has been used to analyse different types of interactions online. This work extends this representation to be able to classify the interaction type online using incrementally updated QTC state chains, create a belief about the state of the world, and transform this high-level descriptor into low-level movement commands. By using QSRs the system becomes invariant to change in the environment, which is essential for any form of long-term deployment of a robot, but most importantly also allows the transfer of knowledge between similar encounters in different environments to facilitate interaction learning. To create a robust qualitative representation of the interaction, the essence of the movement of the human in relation to the robot and vice-versa is encoded in two new variants of QTC especially designed for HRSI and evaluated in several user studies. To enable interaction learning and facilitate reasoning, they are employed in a probabilistic framework using Hidden Markov Models (HMMs) for online classiffication and evaluation of their appropriateness for the task of human-aware navigation. In order to create a system for an autonomous robot, a perception pipeline for the detection and tracking of humans in the vicinity of the robot is described which serves as an enabling technology to create incrementally updated QTC state chains in real-time using the robot's sensors. Using this framework, the abstraction and generalisability of the QTC based framework is tested by using data from a different study for the classiffication of automatically generated state chains which shows the benefits of using such a highlevel description language. The detriment of using qualitative states to encode interaction is the severe loss of information that would be necessary to generate behaviour from it. To overcome this issue, so-called Velocity Costmaps are introduced which restrict the sampling space of a reactive local planner to only allow the generation of trajectories that correspond to the desired QTC state. This results in a exible and agile behaviour I generation that is able to produce inherently safe paths. In order to classify the current interaction type online and predict the current state for action selection, the HMMs are evolved into a particle filter especially designed to work with QSRs of any kind. This online belief generation is the basis for a exible action selection process that is based on data acquired using Learning from Demonstration (LfD) to encode human judgement into the used model. Thereby, the generated behaviour is not only sociable but also legible and ensures a high experienced comfort as shown in the experiments conducted. LfD itself is a rather underused approach when it comes to human-aware navigation but is facilitated by the qualitative model and allows exploitation of expert knowledge for model generation. Hence, the presented work bridges the gap between the speed and exibility of a sampling based reactive approach by using the particle filter and fast action selection, and the legibility of deliberative planners by using high-level information based on expert knowledge about the unfolding of an interaction.

Mobile social software tools have great potential in transforming the way users communicate on the move, by augmenting their everyday environment with pertinent information from their online social networks. A fundamental aspect to the success of these tools is in developing an understanding of their emergent real-world use and also the aspirations of users; this thesis focuses on investigating one facet of this: the exchange of social media. To facilitate this investigation, three mobile social tools have been developed for use on locationaware smartphone handsets. The first is an exploratory social game, 'Gophers' that utilises task oriented gameplay, social agents and GSM cell positioning to create an engaging ecosystem in which users create and exchange geotagged social media. Supplementing this is a pair of social awareness and tagging services that integrate with a user's existing online social network; the 'ItchyFeet' service uses GPS positioning to allow the user and their social network peers to collaboratively build a landscape of socially important geotagged locations, which are used as indicators of a user's context on their Facebook profile; likewise 'MobiClouds' revisits this concept by exploring the novel concept of Bluetooth 'people tagging' to facilitate the creation of tags that are more indicative of users' social surroundings. The thesis reports on findings from formal trials of these technologies, using groups of volunteer social network users based around the city of Lincoln, UK, where the incorporation of daily diaries, interviews and automated logging precisely monitored application use. Through analysis of trial data, a guide for designers of future mobile social tools has been devised and the factors that typically influence users when creating tags are identified. The thesis makes a number of further contributions to the area. Firstly, it identifies the natural desire of users to update their status whilst mobile; a practice recently popularised by commercial 'check in' services. It also explores the overarching narratives that developed over time, which formed an integral part of the tagging process and augmented social media with a higher level meaning. Finally, it reveals how social media is affected by the tag positioning method selected and also by personal circumstances, such as the proximity of social peers.

As the Web grows in size it becomes increasingly important that ways are developed to maximise the efficiency of the search process and index its contents with minimal human intervention. An evaluation is undertaken of current popular search engines which use a centralised index approach. Using a number of search terms and metrics that measure similarity between sets of results, it was found that there is very little commonality between the outcome of the same search performed using different search engines. A semi-automated system for searching the web is presented, the Internet Search Agent (ISA), this employs a method for indexing based upon the idea of "fingerprint types". These fingerprint types are based upon the text and links contained in the web pages being indexed. Three examples of fingerprint type are developed, the first concentrating upon the textual content of the indexed files, the other two augment this with the use of links to and from these files. By looking at the results returned as a search progresses in terms of numbers and measures of content of results for effort expended, comparisons can be made between the three fingerprint types. The ISA model allows the searcher to be presented with results in context and potentially allows for distributed searching to be implemented.

The World Wide Web (WWW) has become an important medium for communicating between people all over the world. It is regarded as a global system and is associated with a wide user and social system diversity. The effects of differing user-groups and their associated cultures on user acceptance of web sites can be significant, and as a result understanding the behaviour of web users in various cultures is becoming a significant concern. The eCulture research project is based on previous classical theories and research in culture. It applies a factorial experimental design strategy (the Taguchi method) in crosscultural usability / acceptability, together with other approaches such as semiotic analysis and card sorting. Two types of analysis, both top-down and bottom-up have been implemented to investigate differences in web site usability and acceptability between users from Mainland China and the United Kingdom. Based on experiments on web sites investigating the relationship between cultural issues and usability lacceptability aspects between Chinese and British web users, several issues, such as cultural factors, cognitive abilities, social semiotic differences and other issues have emerged. One of the goals has been to develop 'cultural fingerprints' for both web sites and users in different cultures. By comparing cultural and site fingerprints, usability and acceptability of web sites can be diagrammatically matched to the target culture. Experiments investigating qualitative factors and quantitative data collection and analysis based on the Taguchi method has led to the successful development of two versions of 'cultural fingerprint' for both web sites and target cultures in the UK and China. It has been possible to relate these studies to a wider body of knowledge, and to suggest ways in which the work may be extended in the future.

Effective use of the World Wide Web grants users increased power over people, time and space. However, its growing ubiquity also means these powers tend to become eroded in non-users. Growth of the Web as a marketplace and as a channel to deliver e-services, results in an ever increasing volume of sensitive information being transacted and stored online. As a result, authentication systems are now being used extensively on the Web. Unfortunately the profusion of Web sites and the large numbers of associated passwords reduces their efficacy and puts severe strain on users’ limited cognitive resources. Authentication systems themselves therefore can act as an additional source of exclusion. However, this step of authentication has up until now, been largely overlooked when considering inclusive design. People may experience a variety of barriers to Internet access: Psychological, Material, Skills and Usage. Existing models of these barriers within the literature are discussed, and a unified model of exclusion is developed and used to identify a series of potential solutions to the various aspects of each barrier. These solutions are classified into 4 separate design goals: Enhanced Usability, Enhanced Accessibility, Reduced End-user Cost and Robust Security. A number of groups who are especially at risk of Web exclusion are also identified. The design goals are used to evaluate existing traditional and image-based passwords. The accessibility component is assessed in terms of twenty-two use scenarios, consisting of a particular user group’s limiting characteristic and strategies the groups are known to use when accessing the Web. The accessibility analysis shows traditional passwords to be less accessible for several groups: • Novice users who experience reduced comparative learnability, efficiency and increased errors. • Mobile phone users, head wand users, eye gaze tracker users, those with reduced manual dexterity/and or tremors accessing principally via a mouse or keyboard, those with impaired ability to select and filter relevant sensory information and low-literacy users accessing via a normal or text to speech browsers. These groups experience reduced comparative efficiency and increased errors. • Users with impaired ability to remember information or sequences and illiterate users accessing via a text-to-speech browser or normal browser. These groups have the most significant issues with passwords, experiencing reduced comparative learnability, memorability, efficiency and increased errors. Image based passwords are found to be more accessible for some of these groups, but are unusable by blind users and less usable by those with visual impairments. Just as Web users are not a uniform, homogenous group, so too is there no homogenous solution to creating usable security. Even so, there may be solutions that are usable and secure given the particular scenario within which they will be used. For this reason, it is important to supply a number of alternatives because as one modality or model of interaction is locked out, another group becomes excluded. One such alternative, a novel scheme called “Musipass”, is trialled in lab-based and large-scale online user participation experiments. Musipass is found to offer superior long-term memorability to a traditional password and users report enjoying the experience of authenticating with music. A security analysis is conducted which shows Musipass to offer comparative or enhanced security compared to a traditional password against a number of well-known attacks.

Although literature reveals that significant efforts have been made to study ICT adoption and diffusion, the diversity of research in terms of theory and methodology is very low. Most studies have relied on traditional adoption theories (e.g., TAM and DOI) and these theories are not capable of providing rich explanantion on how the adoption and post-adoption develop over time. It is argued here that ICT adoption involves multi-dimensional and complex issues. These issues range from how various roles played by actors in emerging ICT are accounted for to ensuring successful adoption. Therefore, this research aims to advance our understanding of emerging ICT adoptions in SMEs from a dynamic process perspective. The specific objectives of this research are to: establish the stages of the dynamic process, identify the key actors and their roles, explore the critical factors affecting the emerging ICT adoption process, identify the challenges and provide recommendations and implications for stakeholders in promoting future adoption and diffusion in UK SMEs. The research adopts a social-technical approach that challenges the ideas of the mainstream thinkers. More specifically, it adopts Actor Network Theory (ANT). The key ANT concepts that influenced the empirical investigation are inscription, translation, framing and stabilisation. The research adopted a qualitative method using face to face interviews. Two rounds of data collection were undertaken. The first round started with a theoretical review, the analysis of relevant literature, and unstructured interviews mainly with small business managers. Eleven interviews were carried out. The second round of interviews was semi-structured with key human actors identified in the first round of interviews. A total of fifteen interviews were conducted. They included the small business manager; SMEs service sector customers, government agencies, SMEs consultants, and IT vendors. The aim was to further explore the dynamic adoption process, the roles and challenges of actors and to validate the outcomes of the findings. The analysis was guided by a hybrid approach of thematic analysis using NVivo software. The study proposed and validated a conceptual framework that illustrates the dynamic process of emerging ICT adoption in SMEs from the Actor Network Theory perspective. This framework helps to understand the adoption process, actors involved, actors’ roles and interactions, and the critical factors. Using the key concepts of ANT as the basis of the investigation, the findings identify a number of key activities associated with the adoption process. These activities include: problem assessment and evaluation, concept generation and evaluation, concept specification, product outsourcing /role delegation, misalignment and alignment of interests, product trial, product modification, adaptation, and impact and problem redefinition. These activities reveal that adoption of emerging ICT in a small business context is not constant, straightforward and certain; instead it is unpredictable, dynamic, and an on-going and reiterative process. ANT concepts were further used to analyse and categorise 20 roles that different actors play, 15 critical factors influencing emerging ICT adoption in SMEs, and the challenges facing actors. While all of these roles, factors, and challenges are critical, in this study, the findings reveal that monitoring and legislation are the most recurring roles at each stage. Furthermore, ease of use, managerial time, shared support, customer focus and adoption costs are the factors affecting the success of multiple stages (three stages). Finally, the thesis presents the contributions and implications for both research and practice in future adoption and diffusion.