This bulletin is a report of one of those side issues, or by-products, of a piece of scientific work which often proves to be more important than the main issue. When, in 1916, the psychological laboratory of the Vocation Bureau of Cincinnati (Ohio) was given an official position in the public-school system, the first task assigned it was that of diagnosing defective children, and transferring them to classes for defectives. The laboratory was quite aware that it would be performing its most important service in this respect by selecting the children for the special classes as young as they could be definitely diagnosed, and while there was still time to train them. A 1918 study of all of the children who had left school after being enrolled in these classes for defectives showed that over 80 percent of them were 12 years or more of age when they were first assigned to special classes. The average length of stay in the special class was only a year and a half, quite too short a time to give the special school an opportunity for training. Meanwhile, repeated failures and unnecessary conflicts with authority had made the children much harder to train than they would otherwise have been. Realizing this state of affairs, even before the statistical proof of it was available, the laboratory began its policy of urging teachers to recommend for examination children in the first and second grades whose academic failure was bad enough to lend any color to the suspicion of mental defect. The contents of this bulletin will be a somewhat detailed report of an observation class of 16 children and the history of each child down to the summer of 1921, together with the general conclusions which can be drawn from the four years of effort and continued observation. Topics covered in this bulletin include: (1) Conditions of the experiment; (2) Scientific methods and standards; (3) Analysis of the group; (4) Methods of teaching; (5) Case reports (children suffering primarily from neglect, defective children, sufferers from special defects, and a psychopathic child); and (6) Discussion of results. An index is also included. (Contains 12 footnotes.) [This bulletin was prepared under the auspices of the Helen S. Trounstine Foundation and constitutes No. 8 in the Foundation's Series of Social Studies. Best copy available has been provided.]