Many people contributed to making this research effort a success. First and foremost, I want to thank my advisor, Calton Pu. He was instrumental in bringing this thesis to fruition. He helped clarify the ideas buried in my "collection of fast assembly-language routines," and his dedication through difficult times encouraged me to keep pushing forward. Without him, this dissertation would not exist.

I am also greatly indebted to the other members of my committee: Dan Duchamp, Bob Sproull, Sal Stolfo, and John Zahorjan. Their valuable insight and timely suggestions helped speed this dissertation to completion.

My sincerest appreciation and deepest "Qua!"s go to Renate Valencia. Her unselfish love and affection and incredible amount of emotional support helped me through some of my darkest hours here at Columbia and gave me the courage to continue on. Thanks also to Matthew, her son, for letting me borrow Goofymeyer, his stuffed dog.

Many other friends in many places have helped in many ways; I am grateful to Emilie Dao for her generous help and support trying to help me understand myself and for the fun times we had together; to John Underkoffler and Clea Waite for their ear in times of personal uncertainty; to Mike Hawley and Olin Shivers, for their interesting conversation, rich ideas, and untiring willingness to "look at a few more sentences"; to Ken Phillips, for the thoughts we shared over countless cups of coffee; to Mort Meyerson, whose generosity in those final days helped to dissipate some of the pressure; to Brewster Kahle, who always has a ready ear and a warm hug to offer; to Domenic Frontiere and family, who are some of the most hospitable people I know; and to all my friends at Cooper Union, who made my undergrad and teaching years there so enjoyable.

I also wish to thank Ming Chiang, Tom Matthews, and Tim Jones, the project students who worked so hard on parts of the Synthesis system. Thanks also go to all the people in the administrative offices, particularly Germaine, who made sure all the paperwork flowed smoothly between the various offices and who helped schedule my thesis defense on record short notice. I particularly want to thank my friends here at Columbia - Cliff Beshers, Shu-Wie Chen, Ashutosh Dutta, Edward Hee, John Ioannidis, Paul Kanevsky, Fred Korz, David Kurlander, Jong Lim, James Tanis, and George Wolberg, to name just a few. The countless dinners, good times, and piggy-back rides we shared helped make my stay here that much more enjoyable.

I also wish to extend special thanks to the people at the University of Washington, especially Ed Lazowska, Hank Levy, Ed Felten, David Keppel (a.k.a. Pardo), Dylan McNamee, and Raj Vaswani, whose boundless energy and happiness always gave me something to look forward to when visiting Seattle or traveling to conferences and workshops. Special thanks to Raj, Dylan, Ed Felten and Jan and Denny Prichard, for creating that `carry' tee shirt and making me feel special; and to Lauren Bricker, Denise Draper, and John Zahorjan for piggy-back rides of unparalleled quality and length.

Thanks goes to Sony corporation for the use of their machine; to Motorola for supplying most of the parts used to build my computer, the Quamachine; and to Burr Brown for their generous donation of digital audio chips.

And finally, I want to thank my family, whose patience endured solidly to the end. Thanks to my mother and father, who always welcomed me home even when I was too busy to talk to them. Thanks, too, to my sister Lucy, sometimes the only person with whom I could share my feelings, and to my brother, Peter, who is always challenging me to a bicycle ride.

In appreciation, I offer to all a warm, heartfelt

- Qua! -