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,