Supervising

Virtual Worlds have virtually exploded in popularity and have experienced significant commercial success. People from all over the globe are experimenting on various aspects that a virtual world can provide. Virtual worlds are deemed to be the future of social networking, online advertising, distant education and potentially surfing the web closely resemble the immersive experience of virtual worlds. Individuals with visual impairments typically use screen readers to access web. Virtual Worlds like Second Life lack textual representation and are not accessible to screen readers. Because virtual worlds are completely owned and created by their users, most of their content doesn't have relevant meta information. This becomes a huge barrier to a text-extraction based approach of making virtual worlds accessible to the visually impaired. This thesis provides a framework which can be used for making virtual worlds accessible to visually impaired individuals. It presents a command based text interface which when connected to a screen reader enables the individuals with visual impairments to access Second Life. It then proposes a technique using which meaningful meta data can be added to the objects in Second Life which can then be retrieved as text and processed to make sense to the screen reader users.

As video games steadily increase in complexity and detail, game engines must also improve to be able to support both rapid and modular development while still maintaining high performance. Component-based architectures have been shown to be effective for allowing developers to rapidly create stunning games with modular components, but unfortunately come with a performance cost over traditional call-and-return systems. This thesis proposes a method that modifies existing component-based game engine architectures to automatically distribute and synchronize work in order to improve performance.

Over the last three decades, video games have evolved from an obscure pastime to a force of change that is transforming the way people perceive, learn about, and interact with the world around them. Video games are not only a popular form of entertainment, but are increasingly being used for other purposes, such as education and health, as well. Despite this increased interest, a significant number of people encounter barriers when playing games, due to a disability. This dissertation helps provide an understanding of how video games can be designed and modified to improve their accessibility features. A large number of existing, accessible games have been studied and analyzed to provide us with insights and understanding as to the importance of encouraging universal access in this field. Though our survey work covered several types of disabilities, the bulk of this dissertation focuses on improving accessibility for the visually impaired. Specific design strategies are illustrated and proven by the development and evaluation of actual blind-accessible games. Case studies are presented for each of the three games we developed during the research period. The first two case studies introduce new strategies for developing blind-accessible games and improv- ing their current state-of-the-art. The third demonstrates a new game for sighted users, the result of playing which, is improved accessibility in another existing game (Second Life). Furthermore, user studies were conducted that focused on the enjoyment, educational, and social interaction aspects of these games while evaluating their ease of access.

Accessibility research has been a part of Human-Computer Interaction since the 1970's. In recent years a small amount of this accessibility research has been applied to the area of games. This previous work applies concepts found in accessibility research to very simple games. This thesis takes the small amount of work done previously and examines it all together. Taking concepts of this work, this thesis then shows how these existing concepts were applied to newer mainstream games. The work on these newer games also led to the creation of a new mechanism that can be applied in further accessibility research, the Rotate & Extend mechanism. Finally, this thesis examines a model that represents the Trade-offs associated with making a game accessible.