Robert Constable will step down as dean of the Faculty of Computing and Information Science (CIS) at Cornell when his second five-year term ends June 30, 2009.

Constable served as chair of the Department of Computer Science for six years before becoming the founding dean of CIS.

"I look forward with considerable enthusiasm to spending more time on research with my superb colleagues and to more regular teaching and writing," Constable said. "However, I am sure that I will miss the stimulating interaction as dean with our alumni, trustees, and with the other Cornell deans, Provost Biddy Martin, her vice provosts and the vice presidents."

Said Provost Biddy Martin: "Dean Constable has been a pioneer in recognizing that computing has become an essential tool in almost every discipline. By conceiving and bringing to life the idea of a universitywide Faculty of Computing and Information Science, he has helped to make that tool accessible in fields as diverse as history, psychology, architecture and plant science. That support has helped Cornell to maintain its position as one of the world's leading research universities. We thank him for his 10 years of innovative and dedicated service."

Martin said she and President David Skorton have decided that the search for a replacement will be internal.

Constable led the creation of an interdisciplinary program that stretches across campus with more than 50 affiliated faculty members, each with a joint appointment in some academic department. CIS also is the umbrella organization for the Program of Computer Graphics and the Department of Statistical Science.

"When I was chair of computer science," Constable recalled, "many departments were hungry to collaborate with us." Coincidentally, a university task force had recommended computing as one of the strategic growth areas for the university. This led to the idea of a "faculty," administratively equivalent to a small college, headed by a dean who could work effectively with the deans of all the colleges and with the resources to hire new faculty members and develop and fund research programs.

Developing information science as a related but separate discipline was part of the plan. According to Constable, the discipline studies "where computing and people meet," centering on what people can do with computing and how humans work with computers, rather than on the theoretical study of how computers work, which is the focus of computer science. CIS now offers a major in information science in three colleges and a minor in every undergraduate college. It also offers a major in computational biology and the tri-institutional graduate program in computational molecular biology in collaboration with Weill Cornell Medical College, Memorial Sloan-Kettering Cancer Center and The Rockefeller University.

Constable believes his two major accomplishments are a concrete definition of what a "faculty" means at Cornell, an idea that could be adopted by other disciplines and other universities, and the creation of an information science program that is already being copied by other universities. "I'm very pleased with the influence we've had," he said. "The model works, and we've defined information science. But it's a ton of work. I'm really eager to get back to research and teaching."

After a one-year leave, Constable plans to return full time to his research on the reliability of computer systems, which he has continued while dean. He and his group made major advances in mathematically proving that computer programs -- and in some cases entire systems, from program down to chip -- do what they claim to do, which is important both for reliability and for security against outside intrusion. Since these proofs are based on mathematical reasoning, the methods also have been applied to proving theorems in pure mathematics.

Constable earned his undergraduate degree at Princeton University in 1964 and his Ph.D. at the University of Wisconsin, Madison, in 1968, the year he came to Cornell.