The Measurement of Intelligence Part 26

25. _Southern._ If the answer is "Southern States," or "Southern California," say: "_Yes; but what does 'southern'

mean?_" Do not credit unless explanation is forthcoming.

26. _Noticeable._ "You notice a thing." (Full credit.)

29. _Civil._ "Civil War." (Failure unless explained.) "It means to be nice." (Full credit.)

30. _Treasury._ Give half credit for definitions like "Valuables,"

"Lots of money," etc.; i.e., if the word is confused with _treasure._

32. _Ramble._ "To go about fast." (Half credit.)

38. _Nerve._ Half credit if the slang use is defined, "You've got nerve," etc.

41. _Majesty._ "What you say to a king." (Full credit.)

45. _Sportive._ "To like sports." (Half credit.) "Playful" or "happy." (Full credit.)

46. _Hysterics._ "You laugh and cry at the same time." "A kind of sickness." "A kind of fit." (All full credit.)

48. _Repose._ "You pose again." (Failure.)

52. _Coinage._ "A place where they make money." (Half credit.)

56. _Dilapidated._ "Something that's very old." (Half credit.)

58. _Conscientious._ "You're careful how you do your work." (Full credit.)

60. _Artless._ "No art." (Failure unless correctly explained.)

61. _Priceless._ "It has no price." (Failure.)

66. _Promontory._ "Something prominent." (Failure unless child can explain what it refers to.)

68. _Milksop._ "You sop up milk." (Failure.)

73. _Harpy._ "A kind of bird." (Full credit.)

80. _Exaltation._ "You feel good." (Full credit.)

85. _Retroactive._ "Acting backward." (Full credit.)

92. _Theosophy._ "A religion." (Full credit.)

It is seen from the above examples that a very liberal standard has been used. Leniency in judging definitions is necessary because the child's power of expression lags farther behind his understanding than is true of adults, and also because for the young subject the word has a relatively less unitary existence.

REMARKS. Our vocabulary test was derived by selecting the last word of every sixth column in a dictionary containing approximately 18,000 words, presumably the 18,000 most common words in the language.

The test is based on the a.s.sumption that 100 words selected according to some arbitrary rule will be a large enough sampling to afford a fairly reliable index of a subject's entire vocabulary. Rather extensive experimentation with this list and others chosen in a similar manner has proved that the a.s.sumption is justified. Tests of the same 75 individuals with five different vocabulary tests of this type showed that the average difference between two tests of the same person was less than 5 per cent. This means that any one of the five tests used is reliable enough for all practical purposes. It is of no special importance that a given child's vocabulary is 8000 rather than 7600; the significance lies in the fact that it is approximately 8000 and not 4000, 12,000, or some other widely different number.

It may seem to the reader almost incredible that so small a sampling of words would give a reliable index of an individual's vocabulary. That it does so is due to the operation of the ordinary laws of chance. It is a.n.a.logous to predicting the results of an election when only a small proportion of the ballots have been counted. It is known that a ballot box contains 600 votes, and if when only 30 have been counted it is found that they are divided between two candidates in the proportion of 20 and 10, it is safe to predict that a complete count will give the two candidates approximately 400 and 200 respectively.[61] In 1914 about 1,000,000 votes were cast for governor in California, and when only 10,000 votes had been counted, or a hundredth of all, it was announced and conceded that Governor Johnson had been reelected by the 150,000 plurality. The completed count gave him 188,505 plurality. The error was less than 4 per cent of the total vote.

[61] Supposing the ballots to have been shuffled.

The vocabulary test has a far higher value than any other single test of the scale. Used with children of English-speaking parents (with children whose home language is not English it is of course unreliable), it probably has a higher value than any three other tests in the scale. Our statistics show that in a large majority of cases the vocabulary test alone will give us an intelligence quotient within 10 per cent of that secured by the entire scale. Out of hundreds of English-speaking children we have not found one testing significantly above age who had a significantly low vocabulary; and correspondingly, those who test much below age never have a high vocabulary.

Occasionally, however, a subject tests somewhat higher or lower in vocabulary than the mental age would lead us to expect. This is often the case with dull children in cultured homes and with very intelligent children whose home environment has not stimulated language development.

But even in these cases we are not seriously misled, for the dull child of fortunate home surroundings shows his dullness in the quality of his definitions if not in their quant.i.ty; while the bright child of illiterate parents shows his intelligence in the aptness and accuracy of his definitions.

We have not worked out a satisfactory method of scoring the quality of definitions in our vocabulary test, but these differences will be readily observed by the trained examiner. Definitions in terms of use and definitions which are slightly inaccurate or hazy are quite characteristic of the lower mental ages. Children of the lower mental age have also a tendency to venture wild guesses at words they do not know. This is especially characteristic of r.e.t.a.r.ded subjects and is another example of their weakness of auto-criticism. One feeble-minded boy of 12 years, with a mental age of 8 years, glibly and confidently gave definitions for every one of the hundred words. About 70 of the definitions were pure nonsense.

This vocabulary test was arranged and partially standardized by Mr.

H. G. Childs and the writer in 1911. Many experiments since then have proved its value as a test of intelligence.

VIII, ALTERNATIVE TEST 1: NAMING SIX COINS

PROCEDURE is exactly as in VI, 5 (naming four coins). The dollar should be shown before the half-dollar.

SCORING. _All six coins must be correctly named._ If a response is changed the rule is to count the second answer and ignore the first.

REMARKS. Binet used nine pieces and required knowledge of all at year X (1908), but at year IX in the 1911 revision. Most other workers have used the same method, with the test located in either year IX or year X.

VIII, ALTERNATIVE TEST 2: WRITING FROM DICTATION

PROCEDURE. Give the child pen, ink, and paper, place him in a comfortable position for writing, and say: "_I want you to write something for me as nicely as you can. Write these words: 'See the little boy.' Be sure to write it all: 'See the little boy.'_"

Do not dictate the words separately, but give the sentence as a whole.

Further repet.i.tion of the sentence is not permissible, as ability to remember what has been dictated is a part of the test. Copy, of course, must not be shown.

SCORING. Pa.s.sed if the sentence is written legibly enough to be easily recognized, and if no word has been omitted. Ordinary mistakes of spelling are disregarded. The rule is that the mistake in spelling must not mutilate the word beyond easy recognition. The performance may be graded by the use of Thorndike's handwriting scale. The handwriting of 8-year-old children who have been in school not less than one year or more than two usually falls between quality 7 and quality 9 on this scale, but we shall, perhaps, not be too liberal if we consider a performance satisfactory which does not grade below quality 6, provided it is not seriously mutilated by errors, omissions, etc.[62]

[62] See scoring card for samples of satisfactory and unsatisfactory performances.

REMARKS. This test found a place in year VIII of Binet's 1908 scale, but has been omitted from all the other revisions, including Binet's own.

Bobertag did not even regard the test as worthy of a trial. The universal criticism has been that it is a test of schooling rather than of intelligence. That the performance depends, in a certain sense, upon special instruction is self-evident. Without such instruction no child of 8 years, however intelligent, would be able to pa.s.s the test. Nature does not give us a conventionalized language, either written or spoken.

It must be acquired. It is also true that a high-grade feeble-minded child, say 8 years of age and of 6-year intelligence, is sometimes (though not always) able to pa.s.s the test after two years of school instruction. It is exceedingly improbable, however, that a feeble-minded subject with less than 6-year intelligence will ever be able to pa.s.s this test, however long he remains in school.

The conclusions to be drawn from these facts are as follows: (1) Inability to pa.s.s the test should not be counted against the child unless it is known that he has had at least a full year of the usual school instruction. (2) Ability to pa.s.s the test after only two years of school instruction is almost certain proof that the child has reached a mental level of at least 6 years. (3) Failure to pa.s.s the test must be regarded as a grave symptom in the case of the child 9 or more years of age who is known to have attended school as much as two years. (4) For mental levels higher than 8 years the test has hardly any diagnostic value, since feeble-minded persons of 8- or 9-year intelligence can usually be taught to write quite legibly.

If the limitations above set forth are kept in mind, the test is by no means without value, and is always worth giving as a supplementary test.

Learning to write simple sentences from dictation is no mean accomplishment. It demands, in the first place, a fairly complete mastery of rather difficult muscular coordinations. Moreover, these coordinations must be firmly a.s.sociated with the corresponding letters and words, for if the writing coordinations are not fairly automatic, so much attention will be required to carry them out that the child will not be able to remember what he has been told to write. The necessity of remembering the pa.s.sage acts as a distraction, and writing from dictation is therefore a more difficult task than writing from copy.

CHAPTER XV

INSTRUCTIONS FOR YEAR IX