f Binet's
entire 54 tests, we have eliminated 3 and relocated 32, leaving only 19
in the positions assigned them by Binet. The 3 eliminated are: repeating
2 digits, resisting suggestion, and "reversed triangle."

The revision is really more extensive than the above figures would
suggest, since minor changes have been made in the scoring of a great
many tests in order to make them fit better the locations assigned them.
Throughout the scale the procedure and scoring have been worked over and
made more definite with the idea of promoting uniformity. This phase of
the revision is perhaps more important than the mere relocation of
tests. Also, the addition of numerous tests in the upper ranges of the
scale affects very considerably the mental ages above the level of
10 or 11 years.

EFFECTS OF THE REVISION ON THE MENTAL AGES SECURED. The most important
effect of the revision is to reduce the mental ages secured in the lower
ranges of the scale, and to raise considerably the mental ages above
10 or 11 years. This difference also obtains, though to a somewhat
smaller extent, between the Stanford revision and those of Goddard and
Kuhlmann.

For example, of 104 adult individuals testing by the Stanford revision
between 12 and 14 years, and who were therefore somewhat above the level
of feeble-mindedness as that term is usually defined, 50 per cent tested
below 12 years by the Goddard revision. That the dull and border-line
adults are so much more readily distinguished from the feeble-minded by
the Stanford revision than by other Binet series is due as much to the
addition of tests in the upper groups as to the relocation of existing
tests.

On the other hand, the Stanford revision causes young subjects to test
lower than any other version of the Binet scale. At 5 or 6 years the
mental ages secured by the Stanford revision average from 6 to 10 months
lower than other revisions yield.

The above differences are more significant than would at first appear.
An error of 10 months in the mental age of a 5-year-old is as serious as
an error of 20 months in the case of a 10-year-old. Stating the error in
terms of the intelligence quotient makes it more evident. Thus, an error
of 10 months in the mental age of a 5-year-old means an error of almost
15 per cent in the intelligence quotient. A scale which tests this much
too low would cause the child with a true intelligence quotient of 75
(which ordinarily means feeble-mindedness or