In order to obtain a fair indication of
the value of intelligence tests in their relationship
to mentally defective children, it will be necessary
to consider the tests from several view-points: it is
proposed to deal with the system:
(a) as a means of diagnosing mental defect;
(b) as a means of grading mental defect;
(c) as a guide to prognosis; and
(d) in its relation to treatment.
We shall then proceed to take up the test reactions of
some definite clinical groups of defectives , and
finally consider the significance of a few individual
The Tests employed, with some observations
on testing technique in cases of (pronounced) mental
The tests employed were these of the Stanford
Revision of the Binet-Simon Tests , as described in
Terman’s "The Measurement of Intelligence" , revised
for application to British children .
Binet-Simon tests were used in preference to
any other scale, because:
( I ) they are still the tests very commonly used*
(II) they have been carefully standardised,
(III) they were specially designed to deal with the
subnormal child, whereas some of the other tests
are meant to detect rather children of superior
In the present investigation it was not found
necessary to use tests above year 16.
A list of tests used is appended.