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
meant to include all who graduate, either by diploma or by certificate.
Any statement made in the following pages of 'time in school' or of
time spent for 'securing graduation' will not include as a part of such
period a semester in which the pupil is absent all or nearly all of the
time, as in the case of absence due to illness.


5. THE SELECTION AND RELIABILITY OF THESE SOURCES OF DATA

By employing data secured only from official school records and in the
manner stated, this study has been limited to those schools that
provide the cumulative pupil records, with continuity and completeness,
for a sufficient period of years. Some schools had to be eliminated
from consideration for our purposes because the cumulative records
covered too brief a period of years. In other schools administrative
changes had broken the continuity of the records, making them difficult
to interpret or undependable for this study. The shortage of clerical
help was the reason given in one school for completing only the records
of the graduates. In addition to the requirements pertaining to
records, only publicly administered and co-educational schools have
been included among those whose records are used. It was also
considered important to have schools representing the large as well as
the small city on the list of those studied. Since many schools do not
possess these important records, or do not recognize their value, it is
quite probable that the conditions prescribed here tended to a