The 1997 Sacks Prize Awarded to I. Farah and T. Scanlon. The co-recipients of the 1997 Sacks Prize are Dr. Ilijas Farah of the University of Toronto and Dr. Tom Scanlon of the Mathematical Sciences Research Institute in Berkeley. Farah received his PhD in June, 1997, at the University of Toronto under the direction of Stevo Todorcevic. His thesis contains remarkable results concerning the structure of analytic ideals and their quotients. Scanlon received his PhD from Harvard University in June, 1997, under the direction of Ehud Hrushovski. His thesis provides a model completion for the theory of differential fields connected by a specialization, together with striking applications of the model theory of valued differential fields to diophantine geometry. The Sacks Prize recognizes the author(s) of the best doctoral dissertation(s) in mathematical logic each year. It was created to honor Professor Gerald Sacks, MIT and Harvard, for his unique contribution to mathematical logic, in particular as advisor to a large number of excellent PhD students. The 1994 award was given to Greg Hjorth of UCLA, the 1995 award was given to Slawomir Solecki of the University of Indiana, and the 1996 award was given jointly to Byunghan Kim of MIT and Itay Neeman of the Harvard Society of Fellows.