This work was supported by the Fannie and John Hertz Foundation and by the Georgia Institute of Technology. The author would like to thank the members of the IGOR research group for their source of provocative ideas, invaluable feedback, and constant monitoring. The author would also like to thank the people who have assisted with the development of various pieces of the theory and the model: Heather Stehman, James Riechel, Gordon Shippey, Tommy Smith, Thomas Tiller, Laurie Bare, and Rajagopal Lakshminarayan. Special thanks are given to Anthony Francis, Jr. for his MOORE memory system which I made extensive use. Similar thanks go to Kavi Mahesh for his COMPERE sentence processing system. Both of these colleagues gave willingly of their time to help my research reach the level it was able to. It is also necessary to acknowledge the great deal of time and effort which my committee gave to me--both the research and the written work has been strengthened by their comments. Finally, I would like to acknowledge the years of guidance and support which my advisor, Ashwin Ram, provided me--he taught me to be a researcher; I am grateful for his tutelage.