The Measurement of Intelligence Part 27

IX, 1. GIVING THE DATE

PROCEDURE. Ask the following questions in order:--

(a) "_What day of the week is it to-day?_"

(b) "_What month is it?_"

(c) "_What day of the month is it?_"

(d) "_What year is it?_"

If the child misunderstands and gives the day of the month for the day of the week, or _vice versa_, we merely repeat the question with suitable emphasis, but give no other help.

SCORING. An error of three days in either direction is allowed for _c_, but _a_, _b_, and _d_ must all be given correctly. If the child makes an error and spontaneously corrects it, the change is allowed, but corrections must not be called for or suggested.

REMARKS. Binet originally located this test in year IX, but unfortunately moved it to year VIII in the 1911 revision. Kuhlmann, G.o.ddard, and Huey all retain it in year IX, where, according to our own data, it unquestionably belongs. With the exception of Binet's 1911 results, the statistics for the test are in remarkably close agreement for children in France, Germany, England, and Eastern and Western United States. It seems that practically all children in civilized countries have ample opportunity to learn the divisions of the year, month, and week, and to become oriented with respect to these divisions. Special instruction is doubtless capable of hastening time orientation to a certain degree, but not greatly. Binet tells of a French _ecole maternelle_ attended by children 4 to 6 years of age, where instruction was given daily in regard to the date, and yet not a single one of the children was able to pa.s.s this test. This is a beautiful ill.u.s.tration of the futility of precocious teaching. In spite of well-meant instruction, it is not until the age of 8 or 9 years that children have enough comprehension of time periods, and sufficient interest in them, to keep very close track of the date. Failure to pa.s.s the test at the age of 10 or 11 years is a decidedly unfavorable sign, unless the error is very slight.

The fact that normal adults are occasionally unable to give the day of the month is no argument against the validity of the test, since the system of tests is so constructed as to allow for accidental failures on any particular test. As a matter of fact, very nearly 100 per cent of normal 12-year-old children pa.s.s this test.

The unavoidable fault of the test is its lack of uniformity in difficulty at different dates. It is easier for school children to give the day of the week on Monday or Friday than on Tuesday, Wednesday, or Thursday. Mistakes in giving the day of the month are less likely to occur at the beginning or end of the month than at any other time, while mistakes in naming the month are most likely to occur then.

It is interesting to compare the four parts of this test in regard to difficulty. Binet and Bobertag both state that ability to name the year comes last, but they give no figures. Our own data show that the four parts of the test are of almost exactly the same difficulty and that this is true at all ages.

IX, 2. ARRANGING FIVE WEIGHTS

Use the five weights, 3, 6, 9, 12, and 15 grams. Be sure that the weights are identical in appearance. The weights may be made as described under V, 1, or they may be purchased of C. H. Stoelting & Co., Chicago, Illinois. If no weights are at hand one of the alternative tests may be subst.i.tuted.

PROCEDURE. Place the five boxes on the table in an irregular group before the child and say: "_See the boxes. They all look alike, don't they? But they are not alike. Some of them are heavy, some are not quite so heavy, and some are still lighter. No two weigh the same. Now, I want you to find the heaviest one and place it here. Then find the one that is just a little lighter and put it here. Then put the next lighter one here, and the next lighter one here, and the lightest of all at this end_ (pointing each time at the appropriate spot). _Do you understand?_"

Whatever the child answers, in order to make sure that he does understand, we repeat the instructions thus: "_Remember now, that no two weights are the same. Find the heaviest one and put it here, the next heaviest here, and lighter, lighter, until you have the very lightest here. Ready; go ahead._"

It is best to follow very closely the formula here given, otherwise there is danger of stating the directions so abstractly that the subject could not comprehend them. A formula like "_I want you to arrange the blocks in a gradually decreasing series according to weight_" would be Greek to most children of 10 years.

If the subject still seems at a loss to know what to do, the instructions may be again repeated. But no further help of any kind may be given. Do not tell the subject to take the blocks one at a time in the hand and try them, and do not ill.u.s.trate by hefting the blocks yourself. It is a part of the test to let the subject find his own method.

Give three trials, shuffling the boxes after each. Do not repeat the instructions before the second and third trials unless the subject has used an absurd procedure in the previous trial.

SCORING. The test is pa.s.sed if the blocks are arranged in the correct order _twice out of three trials_. Always record the order of arrangement and note the number and extent of displacement. Obviously an arrangement like 12-6-15-3-9 is very much more serious than one like 15-12-6-9-3, but we require that two trials be absolutely without error.

Scoring is facilitated if the blocks are marked on the bottom so that they may be easily identified. It is then necessary to exercise some care to see that the subject does not examine the bottom of the blocks for a clue as to the correct order.

REMARKS. Binet originally located this test in year IX, but in his 1911 revision changed it to year VIII. Other revisions have retained it in year IX. The correct location depends upon the weights used and upon the procedure and scoring. Kuhlmann uses weights of 3, 9, 18, 27, 36, and 45 grams, and this probably makes the test easier. Bobertag tried two sets of boxes, one set being of larger dimensions than the other. The larger gave decidedly the more errors. If we require only one success in three trials the test could be located a year or two lower in the scale, while three successes as a standard would require that it be moved upward possibly as much as two years.

Much depends also on whether the child is left to find his own method, and on this there has been much difference of procedure. Kuhlmann, Bobertag, and Wallin ill.u.s.trate the correct method of making the comparison by first hefting and arranging the weights while the subject looks on. We prefer to keep the test in its original form, and with the procedure and scoring we have used it is well located in year IX.

Wallin carries his a.s.sistance still further by saying, after the first block has been placed, "Now, find the heaviest of the four," and after the second has been placed, "Now, find the heaviest of the three," etc.

Finally, when the arrangement has been made, he tells the subject to try them again to make sure the order is correct, allowing the subject to make whatever changes he thinks necessary. This procedure robs the test of its most valuable features. The experiment was not devised primarily as a test of sensory discrimination, for it has long been recognized that individuals who have developed as far as the 9- or 10-year level of intelligence are ordinarily but little below normal in sensory capacity.

Psychologically, the test resembles that of comparing weights in V, 1.

Success depends, in the first place, upon the correct comprehension of the task and the setting of a goal to be attained; secondly, upon the choice of a suitable method for realizing the goal; and finally, upon the ability to keep the end clearly in consciousness until all the steps necessary for its attainment have been gone through. Elementary as are the processes involved, they represent the prototype of all purposeful behavior. The statesman, the lawyer, the teacher, the physician, the carpenter, all in their own way and with their own materials, are continually engaged in setting goals, choosing means, and inhibiting the mult.i.tudinous appeals of irrelevant and distracting ideas.

In this experiment the subject may fail in any one of the three requirements of the test or in all of them. (1) He may not comprehend the instructions and so be unable to set the goal. (2) Though understanding what is expected of him, he may adopt an absurd method of carrying out the task. Or (3) he may lose sight of the end and begin to play with the blocks, stacking them on top of one another, building trains, tossing them about, etc. Sometimes the guiding idea is not completely lost, but is weakened or rendered only partially operative.

In such a case the subject may compare some of the blocks carefully, place others without trying them at all, but continue in his half-rational, half-irrational procedure until all the blocks have been arranged.

It is essential, therefore, to supplement the mere record of success or failure by jotting down a brief but accurate description of the performance. Note any hesitation or inability to grasp the instructions.

Note especially any absurd procedure, such as placing all the blocks without hefting any of them, comparing only some of them, holding them up and shaking them, hefting two at once in the same hand, etc. The ideal method, of course, is to try all the blocks carefully before placing any of them, then to make a tentative arrangement, and finally, to correct this tentative arrangement by means of individual comparisons. A slight departure from this method does not always bring failure, but it renders success less probable. As a rule it is only the very intelligent children of 10 years who think to test out their first arrangement by making a final and additional trial of each block in turn. Contrary to what might be supposed, success is slightly favored by hefting the blocks successively with one hand rather than by taking one in each hand for simultaneous comparison, but as the child cannot be expected to know this, we must regard the two methods as equally logical.

The test of arranging weights has met universal praise. Its special advantage is that it tests the subject's intelligence in the manipulation of _things_ rather than his capacity for dealing with _abstractions_. It tests his ability to do something rather than his ability to express himself in language. It throws light upon certain factors of motor adaptation and practical judgment which play a great part in the everyday life of the average human being. It depends as little upon school, perhaps, as any other test of the scale, and it is readily usable with children of all nations without danger of being materially altered in translation Moreover, it is always an interesting test for the child. Bobertag goes so far as to say that any 8- or 9-year child who pa.s.ses this test cannot possibly be feeble-minded. This may be true; but the converse is hardly the case; that is, the failure of older children is by no means certain proof of mental r.e.t.a.r.dation. The same observation, however, applies equally well to many other of the Binet tests, some of which correlate more closely with true mental age than this one. A rather considerable fraction of normal 12-year-olds fail on it, and it is in fact somewhat less dependable than certain other tests if we wish to differentiate between 9-year and 11-year intelligence. But it is a test we could ill afford to eliminate.[63]

[63] Compare with V, 1.

IX, 3. MAKING CHANGE

PROCEDURE. Ask the following questions in the order here given:--

(a) "_If I were to buy 4 cents worth of candy and should give the storekeeper 10 cents, how much money would I get back?_"

(b) "_If I bought 13 cents worth and gave the storekeeper 15 cents, how much would I get back?_"

(c) "_If I bought 4 cents worth and gave the storekeeper 25 cents, how much would I get back?_"

Coins are not used, and the subject is not allowed the help of pencil and paper. If the subject forgets the statement of the problem, it is permissible to repeat it once, but only once. The response should be made in ten or fifteen seconds for each problem.

SCORING, The test is pa.s.sed if _two out of three_ problems are answered correctly in the allotted time. In case two answers are given to a problem, we follow the usual rule of counting the second and ignoring the first.

REMARKS. Problems of this nature, when thoroughly standardized, are extremely valuable as tests of intelligence. The difficulty of the test, as we have used it, does not lie in the subtraction of 4 from 10, 12 from 15, etc. Such subtractions, when given as problems in subtraction, are readily solved by practically all normal 8-year-olds who have attended school as much as two years. The problems of the test have a twofold difficulty: (1) The statement of the problem must be comprehended and held in mind until the solution has been arrived at; (2) the problem is so stated that the subject must himself select the fundamental operation which applies. The latter difficulty is somewhat the greater of the two, addition sometimes being employed instead of subtraction.

It is just such difficulties as this that prove so perplexing to the feeble-minded. High-grade defectives, although they require more than the usual amount of drill and are likely to make occasional errors, are nevertheless capable of learning to add, subtract, multiply, and divide fairly well. Their main trouble comes in deciding which of these operations a given problem calls for. They can master routine, but as regards initiative, judgment, and power to reason they are little educable. The psychology and pedagogy of mental deficiency is epitomized in this statement.

There has been little disagreement as to the proper location of the test of making change, but various procedures have been employed. Coins have generally been employed, in which case the subject is actually allowed to make the change. Most other revisions have also given only a single problem, usually 4 cents out of 20 cents, or 4 out of 25, or 9 out of 25. It is evident that these are not all of equal difficulty. There is general agreement, however, that normal children of 9 years should be able to make simple change.

IX, 4. REPEATING FOUR DIGITS REVERSED

The series are 6-5-2-8; 4-9-3-7; 3-6-2-9.

PROCEDURE AND SCORING. Exactly as in VII, alternate test 2.[64]

[64] See discussion, p. 207 _ff._

IX, 5. USING THREE WORDS IN A SENTENCE

PROCEDURE The words used are:--

(a) _Boy_, _ball_, _river_.

(b) _Work_, _money_, _men_.

(c) _Desert_, _rivers_, _lakes_.

Say: "_You know what a sentence is, of course. A sentence is made up of some words which say something. Now, I am going to give you three words, and you must make up a sentence that has all three words in it. The three words are 'boy,' 'ball,' 'river.' Go ahead and make up a sentence that has all three words in it._" The others are given in the same way.