est
he may give only the last two or three out of the five or six heard.
Substitutions are also quite frequent, and if so many substitutions are
made as to give a series quite unlike that which the child has heard, it
is an unfavorable sign, indicating weakness of the critical sense which
is so often found with low-level intelligence. In case of extreme
weakness of the power of auto-criticism, the child in response to the
series 9-8-1-7-6-, may say 1-2-3-4-5-6, or perhaps merely a couple of
digits like 8-6, and still express complete satisfaction with his absurd
response. After each series, therefore, the examiner should say, "_Was
it right?_"[54] Very young subjects, however, have a tendency to answer
"yes" to any question of this type, and it is therefore best not to call
for criticism of a performance below the age of 6 or 7 years.

[54] "_Was it wrong?_" is not an equivalent question and should not be
used.

Digit series of a given length are not always of equal difficulty, and
for this reason it is never wise to use series improvised at the moment
of the experiment. We must avoid especially series of regularly
ascending or descending value, the repetition at regular intervals of a
particular digit, and all other peculiarities of arrangement which would
favor the grouping of the digits for easier retention.

It remains to mention two or three further cautions in regard to
procedure. It is best to begin with a series about one digit below the
child's expected ability. If the child has a probable intelligence of
about 6 or 7 years, we should begin with four digits; in case of
probable 10-year intelligence we begin with five digits, etc. On the
other hand, we should avoid beginning too far down, because then the
result is too much complicated by the effects of practice and fatigue.

It is not necessary, and often it is not expedient, to give the digits
tests of all the different years in succession; that is, without other
tests intervening. While this may be permissible with older children, in
young children the power of sustained attention is so weak that no
single kind of test should occupy more than two or three minutes.
Children below 6 or 7 years should ordinarily be given the tests in the
order in which they are listed in the record booklet.

In his 1911 revision of the scale Binet unfortunately shifted this test
from year VII to year VIII. Goddard follows his example, but Kuhlmann
retains it in year VII. Th