Leonard P. Ayres, Edward L. Thorndike, and Andrew S. Draper were leaders of a group of school reformers who were distressed about the large numbers of children who failed to graduate from school. Ayres and other reformers identified two aspects of the problem. First, some students performed unsatisfactorily in school and, consequently, were not promoted from one grade to the next; this falling-back process was called "retardation." Second, other pupils dropped out of school altogether; dropping out was termed "elimination." The Russell Sage Foundation became disturbed about the issue and, in 1908, gave Ayres funding for a research project to document the extent of the problem. Ayres found that among city school systems (considered at that time the best school systems in the country) for each 1,000 students that entered the first grade, only 263 reached the eighth grade, and only 56 reached the...