Method Of Arriving At A Revision
The revision of the scale below the 14-year level was based almost entirely on
the tests of the above-mentioned 1,000 unselected children. The guiding principle
was to secure an arrangement of the tests and a standard of scoring which would
cause the median mental age of the unselected children of each age group
to coincide with the median chronological age. That is, a correct scale
must cause the _average_ child of 5 years to te
t exactly at 5, the
_average_ child at 6 to test exactly at 6, etc. Or, to express the same
fact in terms of intelligence quotient, a correct scale must give a
median intelligence quotient of unity, or 100 per cent, for unselected
children of each age.
If the median mental age resulting at any point from the provisional
arrangement of tests was too high or too low, it was only necessary to
change the location of certain of the tests, or to change the standard
of scoring, until an order of arrangement and a standard of passing were
found which would throw the median mental age where it belonged. We had
already become convinced, for reasons too involved for presentation
here, that no satisfactory revision of the Binet scale was possible on
any theoretical considerations as to the percentage of passes which an
individual test ought to show in a given year in order to be considered
standard for that year.
As was to be expected, the first draft of the revision did not prove
satisfactory. The scale was still too hard at some points, and too easy
at others. In fact, three successive revisions were necessary, involving
three separate scorings of the data and as many tabulations of the
mental ages, before the desired degree of accuracy was secured. As
finally revised, the scale gives a median intelligence quotient closely
approximating 100 for the unselected children of each age from 4 to 14.
Since our school children who were above 14 years and still in the
grades were retarded left-overs, it was necessary to base the revision
above this level on the tests of adults. These included 30 business men
and 150 "migrating" unemployed men tested by Mr. H. E. Knollin, 150
adolescent delinquents tested by Mr. J. Harold Williams, and 50
high-school students tested by the writer.
The extension of the scale in the upper range is such that ordinarily
intelligent adults, little educated, test up to what is called the
"average adult" level. Adults whose intelligence is known from other
sources to be superior are found to test well up toward the "superior
adult" level, and this holds whether the subjects in question are well
educated or practically unschooled. The almost entirely unschooled
business men, in fact, tested fully as well as high-school juniors and
Figure 1 shows the distribution of mental ages for 62 adults, including
the 30 business men and the 32 high-school pupils who were over 16 years
of age. It will be noted that the middle section of the graph represents
the "mental ages" falling between 15 and 17. This is the range which we
have designated as the "average adult" level. Those above 17 are called
"superior adults," those between 13 and 15, "inferior adults." Subjects
much over 15 years of age who test in the neighborhood of 12 years may
ordinarily be considered border-line cases.
The following method was employed for determining the validity of a
test. The children of each age level were divided into three groups
according to intelligence quotient, those testing below 90, those
between 90 and 109, and those with an intelligence quotient of 110 or
above. The percentages of passes on each individual test at or near that
age level were then ascertained separately for these three groups. If a
test fails to show a decidedly higher proportion of passes in the
superior I Q group than in the inferior I Q group, it cannot be regarded
as a satisfactory test of intelligence. On the other hand, a test which
satisfies this criterion must be accepted as valid or the entire scale
must be rejected. Henceforth it stands or falls with the scale as a
When tried out by this method, some of the tests which have been most
criticized showed a high degree of reliability; certain others which
have been considered excellent proved to be so little correlated with
intelligence that they had to be discarded.
After making a few necessary eliminations, 90 tests remained, or 36 more
than the number included in the Binet 1911 scale. There are 6 at each
age level from 3 to 10, 8 at 12, 6 at 14, 6 at "average adult," 6 at
"superior adult," and 16 alternative tests. The alternative tests, which
are distributed among the different groups, are intended to be used only
as substitutes when one or more of the regular tests have been rendered,
by coaching or otherwise, undesirable.
Of the 36 new tests, 27 were added and standardized in the various
Stanford investigations. Two tests were borrowed from the Healy-Fernald
series, one from Kuhlmann, one was adapted from Bonser, and the
remaining five were amplifications or adaptations of some of the earlier
Following is a complete list of the tests of the Stanford revision.
Those designated _al._ are alternative tests. The guide for giving and
scoring the tests is presented at length in Part II of this volume.
_The Stanford revision and extension_
_Year III._ (_6 tests, 2 months each._)
1. Points to parts of body. (3 to 4.)
Nose; eyes; mouth; hair.
2. Names familiar objects. (3 to 5.)
Key, penny, closed knife, watch, pencil.
3. Pictures, enumeration or better. (At least 3 objects enumerated
in one picture.)
(a) Dutch Home; (b) River Scene; (c) Post-Office.
4. Gives sex.
5. Gives last name.
6. Repeats 6 to 7 syllables. (1 to 3.)
Al. Repeats 3 digits. (1 success in 3 trials. Order correct.)
_Year IV._ (_6 tests, 2 months each._)
1. Compares lines. (3 trials, no error.)
2. Discrimination of forms. (Kuhlmann.) (Not over 3 errors.)
3. Counts 4 pennies. (No error.)
4. Copies square. (Pencil. 1 to 3.)
5. Comprehension, 1st degree. (2 to 3.) (Stanford addition.)
"What must you do": "When you are sleepy?" "Cold?" "Hungry?"
6. Repeats 4 digits. (1 to 3. Order correct.) (Stanford addition.)
Al. Repeats 12 to 13 syllables. (1 to 3 absolutely correct, or 2 with
1 error each.)
_Year V._ (_6 tests, 2 months each._)
1. Comparison of weights. (2 to 3.)
3-15; 15-3; 3-15.
2. Colors. (No error.)
Red; yellow; blue; green.
3. AEsthetic comparison. (No error.)
4. Definitions, use or better. (4 to 6.)
Chair; horse; fork; doll; pencil; table.
5. Patience, or divided rectangle. (2 to 3 trials. 1 minute each.)
6. Three commissions. (No error. Order correct.)
_Year VI._ (_6 tests, 2 months each._)
1. Right and left. (No error.)
Right hand; left ear; right eye.
2. Mutilated pictures. (3 to 4 correct.)
3. Counts 13 pennies. (1 to 2 trials, without error.)
4. Comprehension, 2d degree. (2 to 3.) "What's the thing for
you to do":
(a) "If it is raining when you start to school?"
(b) "If you find that your house is on fire?"
(c) "If you are going some place and miss your car?"
5. Coins. (3 to 4.)
Nickel; penny; quarter; dime.
6. Repeats 16 to 18 syllables. (1 to 3 absolutely correct, or 2
with 1 error each.)
Al. Morning or afternoon.
_Year VII._ (_6 tests, 2 months each._)
1. Fingers. (No error.) Right; left; both.
2. Pictures, description or better. (Over half of performance
description:) Dutch Home; River Scene; Post-Office.
3. Repeats 5 digits. (1 to 3. Order correct.)
4. Ties bow-knot. (Model shown. 1 minute.) (Stanford addition.)
5. Gives differences. (2 to 3.)
Fly and butterfly; stone and egg; wood and glass.
6. Copies diamond. (Pen. 2 to 3.)
Al. 1. Names days of week. (Order correct. 2 to 3 checks correct.)
Al. 2. Repeats 3 digits backwards. (1 to 3.)
_Year VIII._ (_6 tests, 2 months each._)
1. Ball and field. (Inferior plan or better.) (Stanford addition.)
2. Counts 20 to 1. (40 seconds. 1 error allowed.)
3. Comprehension, 3d degree. (2 to 3.) "What's the thing for you to
(a) "When you have broken something which belongs to some one
(b) "When you are on your way to school and notice that you are
in danger of being tardy?"
(c) "If a playmate hits you without meaning to do it?"
4. Gives similarities, two things. (2 to 4.) (Stanford addition.)
Wood and coal; apple and peach; iron and silver; ship and
5. Definitions superior to use. (2 to 4.)
Balloon; tiger; football; soldier.
6. Vocabulary, 20 words. (Stanford addition. For list of words used,
see record booklet.)
Al. 1. First six coins. (No error.)
Al. 2. Dictation. ("See the little boy." Easily legible. Pen. 1 minute.)
_Year IX._ (_6 tests, 2 months each._)
1. Date. (Allow error of 3 days in _c_, no error in _a_, _b_, or _d_.)
(a) day of week; (b) month; (c) day of month; (d) year.
2. Weights. (3, 6, 9, 12, 15. Procedure not illustrated. 2 to 3.)
3. Makes change. (2 to 3. No coins, paper, or pencil.)
10--4; 15--12; 25--4.
4. Repeats 4 digits backwards. (1 to 3.) (Stanford addition.)
5. Three words. (2 to 3. Oral. 1 sentence or not over 2 cooerdinate
Boy, river, ball; work, money, men; desert, rivers, lakes.
6. Rhymes. (3 rhymes for two of three words. 1 minute for each part.)
Day; mill; spring.
Al. 1. Months. (15 seconds and 1 error in naming. 2 checks of 3 correct.)
Al. 2. Stamps, gives total value. (Second trial if individual values are
_Year X._ (_6 tests, 2 months each._)
1. Vocabulary, 30 words. (Stanford addition.)
2. Absurdities. (4 to 5. Warn. Spontaneous correction allowed.) (Four
of Binet's, one Stanford.)
3. Designs. (1 correct, 1 half correct. Expose 10 seconds.)
4. Reading and report. (8 memories. 35 seconds and 2 mistakes in
reading.) (Binet's selection.)
5. Comprehension, 4th degree. (2 to 3. Question may be repeated.)
(a) "What ought you to say when some one asks your opinion
about a person you don't know very well?"
(b) "What ought you to do before undertaking (beginning)
something very important?"
(c) "Why should we judge a person more by his actions than by
6. Names 60 words. (Illustrate with clouds, dog, chair, happy.)
Al. 1. Repeats 6 digits. (1 to 2. Order correct.) (Stanford addition.)
Al. 2. Repeats 20 to 22 syllables. (1 to 3 correct, or 2 with 1 error
Al. 3. Form board. (Healy-Fernald Puzzle A. 3 times in 5 minutes.)
_Year XII._ (_8 tests, 3 months each._)
1. Vocabulary, 40 words. (Stanford addition.)
2. Abstract words. (3 to 5.)
Pity; revenge; charity; envy; justice.
3. Ball and field. (Superior plan.) (Stanford addition.)
4. Dissected sentences. (2 to 3. 1 minute each.)
5. Fables. (Score 4; i.e., two correct or the equivalent in half
credits.) (Stanford addition.)
Hercules and Wagoner; Maid and Eggs; Fox and Crow;
Farmer and Stork; Miller, Son, and Donkey.
6. Repeats 5 digits backwards. (1 to 3.) (Stanford addition.)
7. Pictures, interpretation. (3 to 4. "Explain this picture.")
Dutch Home; River Scene; Post-Office; Colonial Home.
8. Gives similarities, three things. (3 to 5.) (Stanford addition.)
Snake, cow, sparrow; book, teacher, newspaper; wool, cotton,
leather; knife-blade, penny, piece of wire; rose, potato,
_Year XIV._ (_6 tests, 4 months each._)
1. Vocabulary, 50 words. (Stanford addition.)
2. Induction test. (Gets rule by 6th folding.) (Stanford addition.)
3. President and king. (Power; accession; tenure. 2 to 3.)
4. Problems of fact. (2 to 3.) (Binet's two and one Stanford
5. Arithmetical reasoning. (1 minute each. 2 to 3.) (Adapted from
6. Clock. (2 to 3. Error must not exceed 3 or 4 minutes.)
6.22. 8.10. 2.46.
Al. Repeats 7 digits. (1 to 2. Order correct.)
"AVERAGE ADULT." (_6 tests, 5 months each._)
1. Vocabulary, 65 words. (Stanford addition.)
2. Interpretation of fables. (Score 8.) (Stanford addition.)
3. Difference between abstract words. (3 real contrasts out of 4.)
Laziness and idleness; evolution and revolution; poverty and
misery; character and reputation.
4. Problem of the enclosed boxes. (3 to 4.) (Stanford addition.)
5. Repeats 6 digits backwards. (1 to 3.) (Stanford addition.)
6. Code, writes "Come quickly." (2 errors. Omission of dot counts
half error. Illustrate with "war" and "spy.") (From Healy and
Al. 1. Repeats 28 syllables. (1 to 2 absolutely correct.)
Al. 2. Comprehension of physical relations. (2 to 3.) (Stanford addition.)
Path of cannon ball; weight of fish in water; hitting distant
"SUPERIOR ADULT." (_6 tests, 6 months each._)
1. Vocabulary, 75 words. (Stanford addition.)
2. Binet's paper-cutting test. (Draws, folds, and locates holes.)
3. Repeats 8 digits. (1 to 3. Order correct.) (Stanford addition.)
4. Repeats thought of passage heard. (1 to 2.) (Binet's and Wissler's
5. Repeats 7 digits backwards. (1 to 3.) (Stanford addition.)
6. Ingenuity test. (2 to 3. 5 minutes each.) (Stanford addition.)