Dependence Of The Scale's Reliability On The Training Of The Examiner
On this point two radically different opinions have been urged. On the
one hand, some have insisted that the results of a test made by other
than a thoroughly trained psychologist are absolutely worthless. At the
opposite extreme are a few who seem to think that any teacher or
physician can secure perfectly valid results after a few hours'
acquaintance with the tests.
The dispute is one which cannot be se
tled by the assertion of opinion,
and, unfortunately, thoroughgoing investigations have not yet been made
as to the frequency and extent of errors made by untrained or partially
trained examiners. The only study of this kind which has so far been
reported is the following:
Dr. Kohs gives the results of tests made by 58 inexperienced teachers
who were taking a summer course in the Training School at Vineland. The
class met three times a week for instruction in the use of the Binet
scale. During the first week the students listened to three lectures by
Dr. Goddard. The second week was given over to demonstration testing.
Each student saw four children tested, and attended two discussion
periods of an hour each. During the third, fourth, and fifth weeks each
student tested one child per week, and observed the testing of two
others. The student was allowed to carry the test through in his own
way, but received criticism after it was finished. Twice a week
Dr. Goddard spent an hour with the class, discussing experimental
procedure. The subjects tested were feeble-minded children whose exact
mental ages were already known, and for this reason it was possible to
check up the accuracy of each student's work.
Kohs's table of results for the trial testing of the 174 children
(1) That 50 per cent of the work was as exact as any one in the
laboratory could make it;
(2) That in an additional 38 per cent the results were within
three fifths of a year of being exact;
(3) That nearly 90 per cent of the work of the summer students was
sufficiently accurate for all practical purposes;
(4) That the records improved during the brief training so that
during the third week only one test missed the real mental age
by as much as a year.
Since hardly any of these students had had any previous experience with
the Binet tests, Dr. Kohs seems to be entirely justified in his
conclusion that it is possible, in the brief period of six weeks, to
teach people to use the tests with a reasonable degree of accuracy.
What shall we say of the teacher or of the physician who has not even
had this amount of instruction? The writer's experience forces him to
agree with Binet and with Dr. Goddard, that any one with intelligence
enough to be a teacher, and who is willing to devote conscientious study
to the mastery of the technique, can use the scale accurately enough to
get a better idea of a child's mental endowment than he could possibly
get in any other way. It is necessary, however, for the untrained person
to recognize his own lack of experience, and in no case would it be
justifiable to base important action or scientific conclusions upon the
results of the inexpert examiner. As Binet himself repeatedly insisted,
the method is not absolutely mechanical, and cannot be made so by
elaboration of instructions.
It is sometimes held that the examination and classification of backward
children for special instruction should be carried out by the school
physicians. The fact is, however, that there is nothing in the
physician's training to give him any advantage over the ordinary teacher
in the use of the Binet tests. Because of her more intimate knowledge of
children and because of her superior tact and adaptability, the average
teacher is perhaps better equipped than the average physician to give
Finally, it should be emphasized that whatever the previous training or
experience of the examiner may have been, his ability to adjust to the
child's personality and his willingness to follow conscientiously the
directions for giving the tests are important factors in his equipment.