Stephen F. Roehrig

Associate Professor of Information Systems and Public Policy
The H. John Heinz III School of Public Policy and Management
Carnegie Mellon University

Welcome to my homepage. As is the custom, I'll give a few particulars about me, and leave it to you to follow pointers to anything that might interest you. The links in the frame on the left will lead you to information about Heinz and CMU, my research, and the courses I teach (these contain syllabi).

I have been at Heinz for six years, joining the faculty after graduating from the Decision Sciences Department (now OPIM) at the Wharton School, University of Pennsylvania. Previously, I have been a research mathematician at two government labs (USCG R&D Center, Groton CT, and Naval Underwater Systems Center, Newport RI). The Heinz School is a lot more fun... My background is in math, but although I've published a few pure math papers (long ago), my work is now much more applied.

My work in uncertain reasoning, much of it done jointly with Steve Kimbrough, has to do with finding and applying new ways to write computer programs which can reason with incomplete or conflicting information. I'm mostly interested in probabilistic methods, but Kimbrough is more in the logicist camp, so he keeps me honest. A few recent papers are available in PostScript format; follow the link to your left.

Since coming to Heinz, I've become interested in problems of privacy and confidentiality in databases. With increasing amounts of data being collected on people and organizations, there is a very real threat of disclosure of sensitive information. Research in this area, led by George Duncan and joined by Ramayya Krishnan and Rema Padman, is currently focusing on the protection of multi-dimensional tables of aggregate data.

Krishnan also has me involved in DecisionNet, dreamed up jointly by him and Hemant Bhargava at the Naval Postgraduate School. The idea here is distributed decision support, through which facilities for model and dataset construction, storage and access are available over the Internet. For two summers now, Krishnan and I have been overseeing the work of Information Networking Institute students in designing and constructing a "Yellow Pages" for Internet-based decision support tools.

I've also provided pointers to work done mostly by two Heinz doctoral students. First, Yuehong Yuan has been looking into the future of the Net, developing economic models of digital libraries. Second, Seng-Su Tsang has invented an extension to conventional cooperative games with side payments. We see this new idea as a means for suggesting equitable divisions of the savings which might accrue if several communities joined forces in building regional facilities (hazardous waste disposal centers, libraries, etc.).

Finally, the administrative details and syllabi for the courses I teach on campus are available. If you're looking for this info, follow the links, but be aware that the syllabi for courses that are currently running may change frequently.