I CEFIIEY THAT I HAVE READ THIS DISSERLATION AND THAT IN MY OPINION IT IS FUITY ADEQUATE, IN SCOPE AND IN QUAIITY, AS A DISSEFIATION FOR THE DEGREE OF DOCIOR OF PHIIOSOPHY YOAV SHOHAM (PHINCIPAL ADVISER I CEFIIEY THAT I HAVE HEAD THIS DISSERIATION AND THAT IN MY OPINION IT IS FUITY ADEQUATE, IN SCOPE AND IN QUAITY, AS A DISSEFIATION FOR THE DEGREE OF DOCIOR OF PHIIOSOPHY TEREY WINOGRAD I CEFIIEY THAT I HAVE HEAD THIS DISSERIATION AND THAT IN MY OPINION IT IS FUITY ADEQUATE, IN SCOPE AND IN QUAlITY, As A DISSEFIATION FOR THE DEGHEE OF DOCIOR O ILOSOPHY ROBERT BARRETT APPROWED FOR THE UNIVERSITY COMMITIEE ON GEADUATE STUDIESI certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Yoav Shoham (Principal Adviser) I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Terry Winograd I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Robert Barrett Approved for the University Committee on Graduate Studies: iii