repairing mode [so that if] one part fails, other parts continue to function” (Business Week Online, 1999a).
9. A considerable economics literature exists on the increasing complexity of technologies as they evolve over time. See, for example, David (1990).
10. The first Tacoma Narrows suspension bridge, near the city of Tacoma, Washington, collapsed as a result of wind-induced vibrations on November 7, 1940, just 4 months after it was opened to traffic. The collapse was attributed to the bridge's structure, which caught the wind instead of letting it pass through. A windstorm caused the bridge to undergo a series of undulations, which were caught on film before its collapse, earning the bridge the nickname “Galloping Gertie. ” Video footage of the bridge's collapse is available online at <http://mecad.uta.edu/~bpwang/me5311/1999/lecture1/intro25.htm>.
11. This material derives from a set of briefing slides entitled “Computer Systems Research: Past and Present” prepared by Butler Lampson from Microsoft Research. The slides are available online at <http://www.research.microsoft.com/lampson/Slides/ ComputerSystemsResearchAbstract.htm >.
12. As evidence of the recognition that issues of security and reliability have received in the policy community, President Clinton signed Presidential Decision Directive 63 on May 22, 1998, which calls for a national effort to ensure the security of critical information infrastructures, such as the telephone system and electric power grid. The directive also established the Critical Infrastructure Assurance Office (CIAO), which was charged with integrating the plans of various industry sectors into a national plan for infrastructure assurance and with coordinating an analysis of the federal government's own dependence on critical infrastructures. Its work to date is captured in CIAO (2000a,b). It builds on the efforts of its predecessor, the President 's Commission on Critical Infrastructure Protection, which was established in July 1996 as the first national effort to address vulnerabilities of infrastructure in the information age. See PCCIP (1997).
13. The 1999 PITAC report outlines nine areas that could be dramatically transformed by information technology. It describes specific transformations in communications, processing information, teaching and learning, the provision of health care, the conduct of commerce, the way people work, the design and manufacture of goods, the conduct of research, and government operations. The full potential of these and similar applications cannot be achieved without a much better fundamental understanding of the applications themselves, the supporting IT, and the relationship between the two. A great deal of research needs to be done to gain this understanding.
14. As noted in a previous CSTB study (CSTB, 1997), most of the people involved in the design and implementation of IT systems are sophisticated users of computing and communications devices. They do not, in general, understand the ways in which IT is used in different applications, nor the more limited technical prowess of the average end user. As a result, it is difficult for researchers and system designers to know what will be easy and gratifying for many of their ultimate customers.