The contributed papers were selected out of 119 submissions at a meeting of the Program Committee on February 6, 1998. Most of the papers present preliminary reports of continuing research. They have been read by the Program Committee, but not formally refereed. It is anticipated that most of them will appear in a more polished form in scientific journals.

The Program Committee is convinced that the general quality of the accepted papers is very high and that the program holds out the prospect of a successful conference. We hope that PODS'98 will appeal to a lot of junior and senior researchers and that it will have a profound impact on the future of the principles of database systems.

The Program Committee also considered papers for two PODS paper awards: the Best Paper Award and the Best Newcomer Paper Award. Two papers were chosen for the PODS'98 Best Paper Award: ``Expressiveness of Structured Document Query Languages Based on Attribute Grammars'' by Frank Neven and Jan Van den Bussche of the University of Limburg and ``A Lower Bound Theorem for Indexing Schemes and its Application to Multidimensional Range Queries'' by Vasilis Samoladas and Daniel Miranker of the University of Texas at Austin. The latter paper was also chosen for the PODS'98 Best Newcomer Paper Award. On behalf of the Program Committee, I extend my congratulations to the authors of both these papers.

The Program Committee would like to thank all those who submitted extended abstracts for consideration, those colleagues who helped in the evaluation, and the sponsoring organizations for their assistance and support. I would like to thank the members of the Program Committee for their excellent work. Special thanks go to the Proceedings Chair Latha Colby, the Publicity Chair Jan Van den Bussche, and to Bart Kuijpers and Marc Gemis for their assistance in preparing the Program Committee meeting. Finally I would also like to thank Dan Suciu, Leonid Libkin, Rick Hull, and Bell Laboratories for hosting the Program Committee meeting.