I would like to thank Sergei Nirenburg for his continual encouragement and contributions to this work. He is the most patient man on the face of this earth and has put up with my foibles, along with several batches of ill health, in a most understanding way. I am also indebted to the other members of my committee, Jaime Carbonell, Robert Frederking and Victor Raskin. They have been remarkably flexible with this long-distance dissertation, in addition to offering much encouragement and advice. Also appreciated are Kavi Mahesh and Evelyne Viegas for their work on the Mikrokosmos project as well as their helpful suggestions with regards to this research. And finally, I would also like to acknowledge and thank David Evans and Barbara DiEugenio, who, along with Sergei Nirenburg, were my advisors at Carnegie Mellon where research on an earlier version of this work was done.