After the meanings of symbols and devices and the methods of recording the facts had been fully explained and carefully studied for the records of any school, the selection of the pupil records was then made, on the basis of the year of the pupils' entrance to the school, including all the pupils who had actually entered and undertaken work. (Pupils who registered but failed to take up school work were entirely disregarded.) These individual records were classified into the failing and the non-failing divisions, then into graduating and non-graduating groups, with the boys and girls differentiated throughout. As fast as the records were read and interpreted into the terms required they were transcribed, with the pupils' names, by the author himself, to large sheets (16x20) from which the tabulations were later made. There was always an opportunity to ask questions and to make appeals for information either to the principal himself or to the secretary in charge of the records. This tended to reduce greatly the danger of mistakes other than those of chance error. The task of transcribing the data was both tedious and prolonged. This process alone required as much as four weeks for each of the larger schools, and without the continued and courteous cooperation of the principals and their assistants it would have been altogether impossible in that time. Some arbitrary decisions and classifications proved necessary in reference to certain facts involved in the data employed in this study. All statements of age will be understood as applying to within the nearest half year; that is, fifteen years of age will mean within the period from fourteen years and a half to fifteen years and a half. The classification in the following pages by school years or semesters (half-years) is dependent upon the time of entrance into school. In this sense, a pupil who entered either in September or in February is regarded as a first semester pupil, however the school classes are named. As promotions are on a subject basis in each of the schools there is no attempt to classify later by promotions, but the time-in-school basis is retained. In reference to school marks or grades, letters are here employed, although four of the eight schools employ percentage grading. Whether the passing mark is 60, as in some of the schools, or 70, as in others, the letter C is used to represent one-third of the distance from the failing mark to 100 per cent; B is used to represent the next third of the distance; and A is used to express the upper third of the distance. The plus and minus signs, attached to the gradings in three of the schools, are disregarded for the purposes of this study, except that when D+ occurred as a conditional passing mark it was treated as a C. Otherwise D has been used to signify a failing grade in a subject, which means that the grade is somewhere below the passing mark. The term 'graduates' is