Joe E. Armstrong is a senior partner of Armstrong Associates, a research firm specializing in technology assessment and related study methodologies. He has had extensive experience in large-scale engineering studies, having directed electronic system laboratories for Sylvania and ESL, Inc., before turning to government and industry consulting. Willis W. Harman is associate director of the Center for the Study of Social Policy at SRI International and is a professor in the Department of Engineering-Economic Systems at Stanford University.