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

intelligence tests.

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.