Using the data gathered by the National Academy of Sciences about the baccalaureate origin of Ph.D. physicists for the periods 1936–1945, 1946–1950, and 1951–1955, the authors detected certain trends in the undergraduate training of Ph.D. physicists. It was found that the undergraduate training of physicists who earned doctorates during the years covered by this study was concentrated in a small proportion of this country's institutions of higher education. This concentration in the top institutions was found to be increasing.
The North Central states lost the lead in the undergraduate training of Ph.D. physicists to the Northeastern states. This is true both numerically and percentagewise. In terms of percentage contribution, the trend is toward the increasing influence of the technical schools (up 4.75%) rather than the colleges (down 5.2%) and universities (up 0.8%). The Ph.D. granting institutions have led the nongranting Ph.D. institutions over this time span and are increasing their percentage contribution. There is a slow trend from the privately controlled to publicly controlled institutions.