Charles Perrow (speaker) is an emeritus professor of sociology at Yale University and a visiting scholar at CISAC. An organizational theorist, his latest research is presented in The Next Catastrophe: Reducing Our Vulnerabilities to Natural, Industrial, and Terrorist Disasters (Princeton, spring 2007). Among his award-winning research is Organizing America: Wealth, Power, and the Origins of American Capitalism (Princeton, 2002), winner of the Max Weber award for best book on organizations from the American Sociological Association in 2003. His recent articles include "Organizational or Executive Failures?" and "Inside the Nuclear Plant's Executive Office," both published in Contemporary Sociology. Perrow currently serves on a National Academy of Science panel on the possibilities of certifying software. He received his BA, MA, and PhD from the University of California, Berkeley, all in sociology.

Peter G. Neumann (respondent) has been in SRI's Computer Science Lab since September 1971. He is concerned with computer systems and networks, trustworthiness/dependability, high assurance, security, reliability, survivability, safety, and many risks-related issues such as voting-system integrity, crypto policy, social implications, and human needs including privacy. He moderates the Association for Computing Machinery's Risks Forum, edits Communications of the ACM's monthly Inside Risks column, chairs the ACM Committee on Computers and Public Policy, and chairs the National Committee for Voting Integrity. He is a Fellow of the ACM, the Institute of Electrical and Electronics Engineers, and the American Association for the Advancement of Science, and is also an SRI Fellow. He received the National Computer System Security Award in 2002 and the ACM SIGSAC (Special Interest Group on Security, Audit, and Control) Outstanding Contributions Award in 2005. He is a member of the U.S. Government Accountability Office Executive Council on Information Management and Technology, and the California Office of Privacy Protection advisory council. He has doctorates from Harvard and Darmstadt.