MEASUREMENT OF IMPROVEMENT AFTER A SECOND INTERVAL OF SIX MONTHS
In view of the fact that one of the experimenters[15] found improvement in school work when her study was extended to cover a second time interval after operation, it was deemed advisable to similarly extend the present investigation in order to determine whether our operated cases showed any improvement after twelve months. To this end, the fifty-six children composing the final groups of the first study, were sought after a second interval of about six months. Conditions made it impossible to give all the retests exactly twelve months from the time of the operation. As a matter of fact, the period ranges from ten to seventeen months. An effort was made to keep the interval between tests equal for the two members of a given pair.
The same tests were given as in the first study. About half of the testing was done by one of the former examiners, but she was obliged to turn the work over to another before it had been completed. The second examiner was highly recommended, and had had training and practical experience in the giving of tests. She was instructed in the methods which had been employed previously, so that conditions were as far as possible kept constant.
The results of the tests are collected in Table XIV. In the first column is given the length of the time interval for each case. It may be seen that the final group was composed of forty-two children, forming twenty-one pairs. There were fifteen pairs which received a second rating in weight; thirteen in height; thirteen in grip; fifteen in tapping, eleven in fatigue as shown by tapping, twenty-one in I.Q., and eighteen in the Healy Test. These numbers while they are smaller than we could wish, would seem to be great enough to indicate
TABLE XIV
Results of the Tests after an Interval of from 10 to 17 Months
| N[16] | Mos. | Weight | Height | Grip | ||||
| Test 1 | Test 3 | Test 1 | Test 3 | Test 1 | Test 3 | |||
| 1 | 15 | 50·4 | 63·5 | 46·0 | 49·7 | 13·0 | 18·0 | |
| 1C | 15 | 53·5 | 62·8 | 46·4 | 49·7 | 11·0 | 15·0 | |
| 2 | 15 | 40·9 | 47·9 | 42·6 | 45·9 | 9·0 | 10·0 | |
| 2C | 17 | 52·3 | 65·5 | 45·2 | 49·8 | 10·0 | 15·0 | |
| 3 | 16 | 55·0 | 67·5 | 47·0 | 50·2 | 12·8 | 13·0 | |
| 3C | 14 | 61·5 | 57·8 | 51·7 | 54·0 | 14·0 | 14·5 | |
| 4 | 13 | 51·1 | 60·2 | 47·5 | 50·5 | 9·0 | ||
| 4C | 13 | 49·4 | 54·2 | 48·9 | 50·8 | 9·5 | ||
| 7 | 14 | 39·9 | 45·8 | 42·9 | 45·6 | 7·0 | 6·0 | |
| 7C | 12 | 38·4 | 42·1 | 41·9 | 43·7 | 9·0 | 14·0 | |
| 8 | 11 | 60·8 | 69·2 | 50·8 | 52·3 | 10·0 | ||
| 8C | 11 | 45·4 | 57·9 | 36·8 | 48·7 | 15·0 | ||
| 10 | 11 | 48·9 | 56·7 | 46·1 | 48·6 | 12·5 | 12·0 | |
| 10C | 11 | 47·1 | 51·8 | 45·6 | 48·1 | 10·0 | 12·0 | |
| 11 | 12 | 47·8 | 55·0 | 45·8 | 49·5 | 11·0 | 11·0 | |
| 11C | 12 | 41·6 | 47·0 | 43·6 | 46·8 | 11·5 | 7·5 | |
| 12 | 12 | 48·0 | 66·5 | 44·8 | 14·0 | |||
| 12C | 11 | 41·0 | 69·6 | 41·5 | 6·0 | |||
| 13 | 12 | 90·0 | 112·0 | 61·3 | 61·8 | 26·5 | 28·5 | |
| 13C | 12 | 74·7 | 88·0 | 56·8 | 60·0 | 22·0 | 27·0 | |
| 14 | 12 | 56·0 | 66·0 | 51·0 | 53·3 | 16·0 | 17·0 | |
| 14C | 12 | 81·9 | 98·0 | 57·9 | 59·5 | 22·0 | 22·5 | |
| 15 | 12 | 57·5 | 51·1 | 15·5 | ||||
| 15C | 10 | 67·2 | 50·1 | 15·0 | ||||
| 16 | 12 | 56·0 | 60·3 | 51·6 | 53·5 | 19·0 | 18·5 | |
| 16C | 11 | 51·2 | 55·0 | 48·7 | 50·1 | 10·0 | 10·0 | |
| 18 | 12 | 58·2 | 47·3 | 18·0 | ||||
| 18C | 11 | 45·3 | 46·7 | 8·0 | ||||
| 19 | 12 | 90·0 | 108·0 | 57·7 | 60·5 | 22·0 | 20·0 | |
| 19C | 11 | 52·4 | 59·0 | 46·7 | 48·0 | 15·0 | 18·0 | |
| 20 | 12 | 44·2 | 47·2 | 11·0 | ||||
| 20C | 11 | 61·3 | 49·6 | 15·0 | ||||
| 21 | 12 | 70·7 | 85·5 | 54·1 | 16·5 | 15.0 | ||
| 21C | 10 | 62·4 | 69·2 | 49·6 | 19·0 | 17·0 | ||
| 23 | 12 | 51·7 | 47·8 | 11·5 | 15·0 | |||
| 23C | 11 | 64·1 | 51·4 | 14·5 | 16·0 | |||
| 27 | 12 | 43·7 | 45·4 | 9·0 | 6·0 | |||
| 27C | 11 | 41·0 | 44·6 | 0 | 9·0 | |||
| 28 | 12 | 71·3 | 78·5 | 54·9 | 56·3 | 23·5 | ||
| 28C | 11 | 74·2 | 85·8 | 53·4 | 55·9 | 21·0 | ||
| N[16] | Tapping | I.Q. | Healy | |||
| Test 1 | Test 3 | (1) | (3) | (1) | (3) | |
| 1 | 135 | 142 | 82 | 93·0 | -25·0 | 11·0 |
| 1C | 106 | 134 | 80 | 85·0 | -50·0 | 11·0 |
| 2 | 105 | 135 | 107 | 113·0 | 28·5 | 24·5 |
| 2C | 152 | 139 | 91 | 86·0 | 3·0 | 19·5 |
| 3 | 136 | 144 | 94 | 91·0 | 21·5 | 15·5 |
| 3C | 135 | 135 | 82 | 96·0 | 17·0 | 25·5 |
| 4 | 103 | 96 | 111 | 8·5 | ||
| 4C | 109 | 83 | 102 | 33·0 | ||
| 7 | 125 | 91 | 93 | - 6·0 | 16·0 | |
| 7C | 105 | 95 | 112 | 4·5 | 11·0 | |
| 8 | 113 | 128 | 91 | 92·0 | 32·5 | |
| 8C | 131 | 121 | 98 | 111·0 | 4·0 | |
| 10 | 68+ 74 | 145+106 | 110 | 116·0 | -12·0 | 11·0 |
| 10C | 70+ 74 | 148+124 | 104 | 107·0 | 27·0 | 48·5 |
| 11 | 125+ 90 | 120+125 | 103 | 102·0 | - 8·0 | 15·5 |
| 11C | 155+125 | 102+112 | 101 | 95·0 | -29·0 | -20·0 |
| 12 | 98+ 69 | 86 | 20·0 | 1·0 | ||
| 12C | 102 | 98 | 90 | -10·0 | 41·5 | |
| 13 | 160+165 | 176+187 | 70 | 61·0 | 43·0 | 62·5 |
| 13C | 150+109 | 188+174 | 66 | 60·0 | -1·5 | 21·5 |
| 14 | 190+172 | 228+215 | 96 | 102·0 | 12·5 | 77·0 |
| 14C | 175+152 | 165+186 | 140 | 138·0 | - 5·0 | 48·5 |
| 15 | 172+167 | 192+186 | 97 | 97·0 | 7·0 | 19·0 |
| 15C | 140+115 | 145+133 | 78 | 98·0 | 1·0 | 54·5 |
| 16 | 145+131 | 65 | 74 | 49·0 | 79·0 | |
| 16C | 145+ 99 | 74 | 81 | 30·0 | 45·5 | |
| 18 | 133+115 | 126+145 | 98 | 101·0 | -13·5 | 13·5 |
| 18C | 100+ 99 | 108+ 92 | 90 | 92·0 | -32·0 | -35·0 |
| 19 | 168+136 | 96 | 97 | 57·5 | 60·5 | |
| 19C | 100+115 | 98 | 90 | -22·0 | -15·0 | |
| 20 | 105+115 | 122+118 | 106 | 116·0 | 55·0 | |
| 20C | 150+120 | 154+154 | 118 | 140·0 | 30·0 | 48·5 |
| 21 | 152+111 | 154+155 | 64 | 66·0 | 20·0 | 38·0 |
| 21C | 140+136 | 174+150 | 86 | 93·0 | 70·5 | 88·0 |
| 23 | 150+119 | 157+157 | 85 | 80·0 | 49·5 | 62·5 |
| 23C | 122+115 | 141+141 | 81 | 88·0 | 4·0 | 64·0 |
| 27 | 108+ 92 | 114+ 95 | 110 | 112·0 | -25·0 | 25·5 |
| 27C | 115+105 | 101+118 | 72 | 98·0 | 2·0 | 39·5 |
| 28 | 150+148 | 176+168 | 81 | 83·0 | 29·5 | 77·5 |
| 28C | 178+148 | 172+157 | 95 | 94·0 | 64·5 | 83·5 |
any very consistent tendency toward improvement. The question, whether or not the results are affected by the differences in time interval, will be considered later.
In weight, the test group showed an average gain of 11·013 pounds, with a median of 9·1 (Table XV). The average gain of the control group was 9·113 pounds and the median 6·8. The gains in the test group are less variable than those of the control. The average of the gains of the test group in excess of those of the control is 1·9 pounds, and the median is 2·2 pounds; while the unreliability of the difference is ± 1·46 The average, then, is only 1·30 P. E. and the median 1·51 P. E.
If we turn to Table III and compare the results there set forth with the results at the end of the second period, we find the gains of the test group exceed those of the control in the following manner.
TABLE XV
Weight, Second Retests, 15 Pairs
| N[16] | Test Group (A) | Control Group (B) | |||||
| Test 1 | Test 3 | Gain | Test 1 | Test 3 | Gain | A-B | |
| 12 | 48 | 66·5 | 18·5 | 69·6 | 28·6 | -10·1 | |
| 2 | 40·9 | 47·9 | 7 | 52·3 | 65·5 | 13·2 | -6·2 |
| 14 | 56 | 66 | 10 | 81·9 | 98 | 16·1 | -6·1 |
| 28 | 71·3 | 78·5 | 7·2 | 74·2 | 85·8 | 11·6 | -4·4 |
| 8 | 60·8 | 69·2 | 8·4 | 45·4 | 57·9 | 12·5 | -4·1 |
| 16 | 56 | 60·3 | 3·7 | 51·2 | 55 | 3·8 | -·1 |
| 11 | 47·8 | 55 | 7·2 | 41·6 | 47 | 5·4 | 1·8 |
| 7 | 39·9 | 45·8 | 5·9 | 38·4 | 42·1 | 3·7 | 2·2 |
| 10 | 48·9 | 56·7 | 7·8 | 47·1 | 51·8 | 4·7 | 3·1 |
| 1 | 50·4 | 63·5 | 13·1 | 53·5 | 62·8 | 9·3 | 3·8 |
| 4 | 51·1 | 60·2 | 9·1 | 49·4 | 54·2 | 4·8 | 4·3 |
| 21 | 70·7 | 85·5 | 14·8 | 62·4 | 69·2 | 6·8 | 8 |
| 13 | 90 | 112 | 22 | 74·7 | 88 | 13·3 | 8·7 |
| 19 | 90 | 108 | 18 | 52·4 | 59 | 6·6 | 11·4 |
| 3 | 55 | 67·5 | 12·5 | 61·5 | 57·8 | -3·7 | 16·2 |
| Av. | 58·45 | 69·50 | 11·01 | 55·13 | 63·58 | 9·11 | 1·9 |
| M | 9·1 | 6·8 | 2·2 | ||||
| 75%ile | 13·52 | 12·67 | 5·22 | ||||
| 25%ile | 7·15 | 4·47 | -4·07 | ||||
| Q | 3·18 | 4·1 | 4·65 | ||||
| P. E. (distribution) | 3·81 | 4·19 | 6·1 | ||||
| P. E. (average) | ±1·00 | ±1·07 | ±1·46 | ||||
| Av. = 1·30 P. E. | |||||||
| M. = 1·51 P. E. | |||||||
| 6 months | 12 months | |
| Average of gains in test group in excess of control | 1·37 | 1·90 |
| Median | 1·20 | 2·20 |
| P. E. of difference | ±·48 | ±1·46 |
| Average in terms of P. E. | 2·85 | 1·30 |
| Median in terms of P. E. | 2·80 | 1·51 |
After a twelve months' interval, therefore, the actual average and median gains are slightly larger than after the first six months, but the variability is very much greater. Therefore, when expressed in terms of P. E., the gains are smaller. One of the test group cases (No. 13) who had gained 8 pounds after six months, gained 14 pounds in the second period of six months, making a total gain of 22 pounds. This gain is exceeded, however, by one in the control group (No. 12) who gained 3·5 pounds in six months, and 25·1 pounds more in the ensuing five months. This is certainly an enormous gain for five months, under any circumstances. Turning to Table XIV we find no corresponding gain in I.Q. for this child. Indeed there is a loss of five points.
Other children in the test group who made large gains, were case 12, with a gain of 18·5 pounds after twelve months, compared with 4·5 pounds after six months; case 19, gain of 6·3 pounds after first six months, and 18 pounds after 12 months; case 21, whose gain after the first period was 5·8 pounds, but who gained 14·8 pounds after twelve months. In these cases the gain in the second period greatly exceeds that for the first.
TABLE XVI
Height, Second Retests, 13 Pairs
| N[16] | Test Group (A) | Control Group (B) | |||||
| Test 1 | Test 3 | Gain | Test 1 | Test 3 | Gain | A-B | |
| 13 | 61·3 | 61·8 | ·5 | 56·8 | 60·0 | 3·2 | -2·7 |
| 2 | 42·6 | 45·9 | 3·3 | 45·2 | 49·8 | 4·6 | -1·3 |
| 28 | 54·9 | 56·3 | 1·4 | 53·4 | 55·9 | 2·5 | -1·1 |
| 8 | 50·8 | 52·3 | 1·5 | 46·8 | 48·7 | 1·9 | - ·4 |
| 10 | 46·1 | 48·6 | 2·5 | 45·6 | 48·1 | 2·5 | ·0 |
| 1 | 46·0 | 49·7 | 3·7 | 46·4 | 49·7 | 3·3 | ·4 |
| 11 | 45·8 | 49·5 | 3·7 | 43·6 | 46·8 | 3·2 | ·5 |
| 16 | 51·6 | 53·5 | 1·9 | 48·7 | 50·1 | 1·4 | ·5 |
| 14 | 51·0 | 53·3 | 2·3 | 57·9 | 59·5 | 1·6 | ·7 |
| 3 | 47·0 | 50·2 | 3·2 | 51·7 | 54·0 | 2·3 | ·9 |
| 7 | 42·9 | 45·6 | 2·7 | 41·9 | 43·7 | 1·8 | ·9 |
| 4 | 47·5 | 50·5 | 3·0 | 48·9 | 50·8 | 1·9 | 1·1 |
| 19 | 57·7 | 60·5 | 2·8 | 46·7 | 4·8 | 1·3 | 1·5 |
| Av. | 49·63 | 52·17 | 2·5 | 48·74 | 51·16 | 2·42 | ·08 |
| M | 2·7 | 2·3 | ·5 | ||||
| 75%ile | 3·15 | 2·85 | ·85 | ||||
| 25%ile | 1·6 | 1·75 | ·92 | ||||
| Q | ·775 | ·65 | ·885 | ||||
| P. E. (distribution) | ·66 | ·78 | ·82 | ||||
| P. E. (average) | ±·18 | ±·22 | ±·28 | ||||
| Av.=·29 P. E. | |||||||
| M.=1·79 P. E. | |||||||
In weight, then, the mean gain of the test group over and above the control continues to increase through the second period of six months. The variability, however, increases enormously, which fact is due possibly to varying conditions which may enter in during the longer period to affect the health and thus lessen the gain of some of the children.
In order to determine whether the slight inequalities in interval length have any considerable effect on the results, we have calculated the relation between the length of interval and amount of improvement. The coefficient of correlation by the method of rank differences is equal to ·03. The small number of cases renders the unreliability of correlation very great, but we can at least say that there is no consistent relationship between improvement and time interval, within the narrow limits here set. We are probably justified in taking twelve months as the interval, since such was the case in eight out of the fifteen test cases, while the greatest variation above this made was four months, and below it, one month.
The gains in height after twelve months are shown in Table XVI. The average gain of test group in excess of control, is only ·08 inches, and the median ·5 inches. Variability is about the same as at the end of six months, P. E. ± ·28. The average is only ·29 P. E., but the median is a little larger, 1·79 P. E. If these measures are compared with the results after the first period, we have:
| 6 months | 12 months | |
| Average of gains of test group in excess of control | ·16 | ·08 |
| Median of gains of test group in excess of control | ·20 | ·50 |
| P. E. of difference | ·16 | ·28 |
| Average in terms of P. E. | 1·00 | ·29 |
| Median in terms of P. E. | 1·25 | 1·79 |
There seems to be little gain in height after the first period. Test cases 1 and 11 each show a gain of 3·7 inches after fifteen and twelve months respectively, compared with gains after six months of 1·6, and 1·9 inches. But case 2 in the control group, makes still greater comparative gain, +1·8 inches after six months and 4·6 inches after seventeen months. In this case there are almost six additional months for the child to grow, which may account for the larger gain. Control case 1, however, may be compared with his partner, mentioned above, since the interval between tests was the same for both. This boy grew 1·4 inches in six months, and 3·3 inches after 15 months. This is practically equal growth with test case 1. Control case 11 also shows relatively great growth during 12 months, +3·2 inches, whereas the growth in six months was only 1·3 inches. Out of the test group, 7 cases gained more in the first period of six months, than in the second, while only 6 gained more in the second than in the first. Of the control group, 7 cases made more than half of their total gain during the second six months of the total twelve months' period. Since this is true, it seems likely that whatever increase in growth we find during the second half of the twelve months' interval, may be explained by incidental causes, and that so far as actual gain in height is considered, there is no further effect from the operations, after six months.
As was mentioned in the previous chapter, height and weight are of less significance when considered alone, than when taken in relation to each other and to the age of the individual. The gain in this weight-height-age relationship following upon operation for adenoids and tonsils, will be considered in the same manner as were weight and height gains. We have, then:
TABLE XVII
Height-Weight Relationship, Second Retests, 13 Pairs Showing changes in per cent over or underweight after 12 months' interval
| N[16] | Test Group (A) | Control Group (B) | ||||||
| Test 1 | Test 3 | Change | Test 1 | Test 2 | Change | A-B | ||
| 8 | - 1 | + 7 | + 8 | -13 | 0 | +13 | - 5 | |
| 16 | -16 | -17 | - 1 | -13 | - 9 | + 4 | - 5 | |
| 11 | - 3 | - 6 | - 3 | - 9 | -10 | - 1 | - 2 | |
| 14 | -13 | - 6 | + 7 | - 5 | + 4 | + 9 | - 2 | |
| 19 | + 6 | +10 | + 4 | + 1 | + 7 | + 6 | - 2 | |
| 28 | - 7 | - 4 | + 3 | 0 | + 5 | + 5 | - 2 | |
| 10 | - 1 | 0 | + 1 | - 6 | - 6 | 0 | + 1 | |
| 7 | - 8 | - 8 | 0 | - 7 | - 9 | - 2 | + 2 | |
| 2 | - 8 | - 4 | + 4 | + 9 | +10 | + 1 | + 3 | |
| 4 | - 7 | - 4 | + 3 | -15 | -15 | 0 | + 3 | |
| 1 | 0 | + 6 | + 6 | + 8 | + 5 | - 3 | + 9 | |
| 13 | -13 | + 6 | +19 | -11 | -12 | - 1 | +20 | |
| 3 | + 6 | +13 | + 7 | - 5 | -20 | -15 | +22 | |
| Av. | - 5 | -·54 | 4·46 | - 5·08 | 3·85 | 1·23 | 3·23 | |
| M | 4 | - 2 | 6 | |||||
| 75%ile | 6·75 | 2·75 | 3 | |||||
| 25%ile | - 2·50 | 2·75 | - 2 | |||||
| Q | 4·625 | 2·75 | 2·50 | |||||
| P. E. (distribution) | 2·54 | 3·23 | 5·23 | |||||
| P. E. (average) | ± ·71 | ± ·90 | ± 1·15 | |||||
| Av.=2·81 P. E. | ||||||||
| M. =5·22 P. E. | ||||||||
| 6 months | 12 months | |
| Average of gains of test group in excess of control | 1·83 | 3·23 |
| Median of gains of test group in excess of control | 4·00 | 6·00 |
| P. E. of difference | ·91 | 1·15 |
| Average in terms of P. E. | 2·02 | 2·81 |
| Median in terms of P. E. | 4·40 | 5·22 |
The mean of the actual gains in the second period exceeds that of the first. Again the second group of results is more variable, decreasing the reliability. There seems, however, to be a definite increase in the net gain of the test group during a second six months' period. Some individual cases may be cited. The greatest gain after six months is 8 units in the test case, matched by an equal gain of 8 units in the control group. After twelve months, the test group shows one gain of 19 units, the highest gain in the control group being 13. Six cases in the test group, and 13 in the control had lost at the end of six months, but after twelve months, all but 2 of the test cases showed a gain, and all but 5 of the controls. In 10 test cases out of the total 13, more than half of the gain occurred during the second six months. In the control group, six of the cases made more than half of their gain during the second six months, and the second interval gains of the other 7 cases exceeded the 50 per cent mark by so little that they may be accounted for by chance.
These results seem to indicate a slight but actual increase in the net gain of the test group during the second six months of the experiment, and an accompanying growth in the variability of these gains.
It will be remembered that the results described in the previous chapter show no gain in strength of grip as a result of operation. Comparison of the 13 cases tested after the second interval, with the 16 cases at the end of the first, gives results as follows:
TABLE XVIII
Gain in Grip, Second Retest, 13 Pairs
| N[16] | Test Group (A) | Control Group (B) | |||||
| Test 1 | Test 2 | Gain | Test 1 | Test 2 | Gain | A-B | |
| 7 | 7 | 6 | -1 | 9 | 14 | 5 | -6 |
| 19 | 22 | 20 | -2 | 15 | 18 | 3 | -5 |
| 2 | 9 | 10 | 1 | 10 | 15 | 5 | -4 |
| 27 | 9 | 6 | -3 | 8 | 9 | 1 | -4 |
| 13 | 26·5 | 28·5 | 2 | 22 | 27 | 5 | -3 |
| 10 | 12·5 | 12 | -·5 | 10 | 12 | 2 | -2·5 |
| 16 | 19 | 18·5 | -·5 | 10 | 10 | - ·5 | |
| 3 | 12·5 | 13 | ·5 | 14 | 14·5 | ·5 | |
| 14 | 16 | 17 | 1 | 22 | 22·5 | ·5 | ·5 |
| 21 | 16·5 | 15 | -1·5 | 19 | 17 | -2 | ·5 |
| 1 | 13 | 18 | 5 | 11 | 15 | 4 | 1 |
| 23 | 11·5 | 15 | 3·5 | 14·5 | 16 | 1·5 | 2 |
| 11 | 11 | 11 | 11·5 | 7·5 | -4 | 4 | |
| Av. | 14·27 | 14·61 | ·34 | 13·54 | 15·19 | 1·65 | -1·31 |
| M | 0 | 1·5 | -1·5 | ||||
| 75%ile | 1·25 | 3·75 | ·62 | ||||
| 25%ile | -1·38 | ·12 | -·4 | ||||
| Q | 1·31 | 1·81 | ·51 | ||||
| P. E. (distribution) | 1·34 | 1·65 | 2·31 | ||||
| P. E. (average) | ± ·37 | ±·46 | ±·59 | ||||
| Av.=-2·22 P. E. | |||||||
| M.=-2·54 P. E. | |||||||
| 6 months | 12 months | |
| Average of gains of test group in excess of control | -·24 | -1·31 |
| Median of gains of test group in excess of control | -1·00 | -1·50 |
| P. E. of difference | ±·48 | ±·59 |
| Average in terms of P. E. | -·50 | -2·22 |
| Median in terms of P. E. | -2·08 | -2·54 |
The greatest gain in the test group after twelve months is 5 Kg. (Case 1). During the first six months this case lost 1 Kg. There are two gains of 5 Kg. in the control group. Of these two (cases 7 and 13) had gained 1 Kg. during the first interval and another (case 2) 2 Kg. The greatest loss in the test group after the twelve months' period was 3 Kg., by case 27, which had already lost this amount at the end of six months. The greatest loss in the control group was suffered by case 11, a loss of 4 Kg., all in the second period. After the first period, 9 out of 16 cases in the test group gained in strength of grip, and 13 in the control group. After the second period, the test cases showing gain numbered only 7 out of 13, while all of the control cases had gained except 2. Of the test group 8 cases in the second period either gained less than half of the amount they had improved in the first period, or dropped from the scores they had made at that time. The corresponding numbers for the control group are 6 and 7.
There is evidently no improvement in strength of grip twelve months after operation. The unreliability of the results is very great. However, there is certainly no tendency toward improvement. Why this should be is a question. It may be that the change in examiners is partly responsible, for performance in this test is influenced to a surprising extent by the manner in which it is presented.
TABLE XIX
Tapping—Second Retest, 15 Pairs
| N[16] | Test Group (A) | Control Group (B) | |||||
| Test 1 | Test 3 | Gain | Test 1 | Test 3 | Gain | A-B | |
| 21 | 152 | 154 | 2 | 149 | 174 | 34 | -32 |
| 13 | 160 | 176 | 16 | 150 | 188 | 38 | -22 |
| 1 | 135 | 142 | 7 | 106 | 134 | 28 | -21 |
| 18 | 133 | 126 | - 7 | 100 | 108 | 8 | -15 |
| 23 | 150 | 157 | 7 | 122 | 141 | 19 | -12 |
| 10 | 68 | 145 | 77 | 70 | 148 | 78 | - 1 |
| 3 | 136 | 144 | 8 | 135 | 135 | 0 | 8 |
| 20 | 105 | 122 | 17 | 150 | 154 | 4 | 13 |
| 15 | 172 | 192 | 20 | 140 | 145 | 5 | 15 |
| 27 | 108 | 114 | 6 | 115 | 101 | -14 | 20 |
| 8 | 113 | 128 | 15 | 131 | 121 | -10 | 25 |
| 28 | 150 | 176 | 26 | 178 | 172 | - 6 | 32 |
| 2 | 105 | 135 | 30 | 152 | 139 | -13 | 43 |
| 11 | 125 | 120 | - 5 | 155 | 102 | -53 | 48 |
| 14 | 190 | 228 | 38 | 175 | 165 | -10 | 48 |
| Av. | 133·47 | 150·6 | 17·13 | 134·6 | 141·8 | 7·2 | 9·93 |
| M | 15 | 4 | 11 | ||||
| 75%ile | 21·5 | 21·5 | 26·75 | ||||
| 25%ile | 5 | -10·75 | -16·5 | ||||
| Q | 8·25 | 16·12 | 21·62 | ||||
| P. E. (distribution) | 10·13 | 17·2 | 22·07 | ||||
| P. E. (average) | ± 2·67 | ± 4·53 | ± 5·26 | ||||
| Av.=1·89 P. E. | |||||||
| M. =2·09 P. E. | |||||||
There were 15 pairs of cases who performed the tapping test at the end of twelve months. Comparison with the 21 pairs after six months yields the following results:
| 6 months | 12 months | |
| Average of gains of test group in excess of control | - ·09 | 9·93 |
| Median of gains of test group in excess of control | 0·00 | 11·00 |
| P. E. of difference | ±3·10 | ± 5·26 |
| Average in terms of P. E. | ·03 | 1·89 |
| Median in terms of P. E. | 0·00 | 2·09 |
The gain in the second interval is greater for the tapping test than for any of the tests yet described. After the first six months there is no gain. At the end of ten months the average gain is 9·93, and the median 11 taps per half minute. After six months' interval, 11 of 21 test group cases had lost. At the end of twelve months, only 2 out of 15 had lost. The control group, on the other hand, lost in 11 out of 21 cases after six months, and in 6 out of 15 at the end of twelve months. All but one of the test group cases made more than half of their gain in the second period. Of the control group only 7 cases did this. The variability of gains after 12 months is about equal to the variability at the end of six months.
Strangely enough, decrease in fatigueability as described in the previous chapter does not show itself after 12 months. In fact, the negligible loss in ability noticeable after six months has increased after a period of twelve months. In only 4 out of 11 test group cases, is the gain in the second period equal to that of the first, a similar result to that found in the control group, where 5 out of the 11 cases made half their total gain in the second interval. The results are compared below.
| 6 months | 12 months | |
| Average of gains of test group in excess of control | -·020 | - ·060 |
| Median of gains of test group in excess of control | -·015 | - ·090 |
| P. E. of difference | ±·040 | ± ·036 |
| Average in terms of P. E. | -·500 | -1·660 |
| Median in terms of P. E. | -·380 | -2·500 |
TABLE XX
Tapping for Fatigue, Second Retests, 11 Pairs
| N[16] | Test Group (A) | Control Group (B) | |||||
| Test 1 | Test 3 | Gain | Test 1 | Test 3 | Gain | A-B | |
| 20 | -·10 | ·03 | -·13 | ·20 | ·0 | ·20 | -·33 |
| 27 | ·15 | ·17 | -·02 | ·09 | -·17 | ·26 | -·28 |
| 10 | -·09 | ·27 | -·36 | ·06 | ·16 | -·10 | -·26 |
| 14 | ·09 | ·05 | ·04 | ·13 | -·13 | ·26 | -·22 |
| 13 | -·03 | -·06 | ·03 | ·27 | ·07 | ·20 | -·17 |
| 28 | ·01 | ·05 | -·04 | ·17 | ·10 | ·07 | -·11 |
| 15 | ·03 | ·03 | ·0 | ·18 | ·08 | ·10 | -·10 |
| 23 | ·11 | ·0 | ·11 | ·06 | ·0 | ·06 | ·05 |
| 21 | ·27 | -·01 | ·28 | ·29 | ·14 | ·15 | ·13 |
| 11 | ·28 | -·04 | ·32 | ·11 | -·01 | ·12 | ·20 |
| 18 | ·14 | -·15 | ·29 | ·01 | ·15 | -·14 | ·43 |
| Av. | ·078 | ·031 | ·047 | ·143 | ·035 | ·107 | -·06 |
| M | ·03 | ·12 | -·09 | ||||
| 75%ile | ·153 | ·20 | ·07 | ||||
| 25%ile | -·062 | ·02 | -·275 | ||||
| Q | ·107 | ·09 | ·172 | ||||
| P. E. (distribution) | ·087 | ·093 | ·19 | ||||
| P. E. (average) | ±·02 | ±·03 | ±·036 | ||||
| Av.=-1·66 P. E. | |||||||
| M.=-2·50 P. E. | |||||||
The point of greatest interest in the present study is, as has been said, improvement in intelligence. Does operation for adenoids and tonsils result in improvement in intelligence, as measured by I.Q.? If such improvement does not manifest itself after six months, can it be found after a second period of the same length? The latter question is answered by observation of Table XXI and attention to the following facts, gathered from the 21 pairs of cases who were given intelligence tests after the twelve months' interval.
| 6 months | 12 months | |
| Average of gains of test group in excess of control | -1·035 | -3·14 |
| Median of gains of test group in excess of control | -1 | -3 |
| P. E. of difference | ±1·10 | ±1·84 |
| Average in terms of P. E. | - ·94 | -1·71 |
| Median in terms of P. E. | - ·99 | -1·63 |
The result after twelve months remains the same as that after the six months' interval. A gain or loss of two or three points in I.Q. is negligible, so that the mean gain of the test group in excess of the control is practically zero at the end of each period. Variability increases with the length of the interval. One case in the test group (case 4) gained nothing in six months, but showed a gain of 15 points after 13 months. However, there is a control case to match this,—case 15, who gained 1 point in the first six months and 20 points after 10 months. Case 20 in the test group lost 4 points in the first six months, but gained back these and 10 additional in the second period. But control No. 1 gained 5 points in the second interval after having lost 4 in the first.
On the other hand several cases lost in the second period, as compared with the first. Test group case 7, for example, gained 8 points in the first six months, and lost 6 of them in the second. Case 3 in the same group lost 3 points in the first period, and failed to regain any of them. Case 12 lost 3 points in six months and 9 more before the end of 12 months. In the control group, case 23 gained 15 pounds in the first six months and lost eight of them in the second. Summing up gains and losses in the second period, for both groups:
TABLE XXI
I.Q., Second Retests, 21 Pairs
| N[16] | Test Group (A) | Control Group (B) | |||||
| Test 1 | Test 3 | Gain | Test 1 | Test 3 | Gain | A-B | |
| 27 | 110 | 112 | 2 | 72 | 98 | 26 | -24 |
| 15 | 97 | 97 | 78 | 98 | 20 | -20 | |
| 3 | 94 | 91 | -3 | 82 | 96 | 14 | -17 |
| 7 | 91 | 93 | 2 | 95 | 112 | 17 | -15 |
| 20 | 106 | 116 | 10 | 118 | 140 | 22 | -12 |
| 23 | 85 | 80 | -5 | 81 | 88 | 7 | -12 |
| 8 | 91 | 92 | 1 | 98 | 111 | 13 | -12 |
| 12 | 98 | 86 | -12 | 98 | 91 | -7 | -5 |
| 21 | 64 | 66 | 2 | 86 | 93 | 7 | -5 |
| 4 | 96 | 111 | 15 | 83 | 102 | 19 | -4 |
| 13 | 70 | 61 | -9 | 66 | 60 | -6 | -3 |
| 18 | 98 | 101 | 3 | 90 | 92 | 2 | 1 |
| 16 | 65 | 74 | 9 | 74 | 81 | 7 | 2 |
| 10 | 110 | 116 | 6 | 104 | 107 | 3 | 3 |
| 28 | 81 | 83 | 2 | 95 | 94 | -1 | 3 |
| 11 | 103 | 102 | -1 | 101 | 95 | -6 | 5 |
| 1 | 82 | 93 | 11 | 80 | 85 | 5 | 6 |
| 14 | 96 | 102 | 6 | 140 | 138 | -2 | 8 |
| 19 | 96 | 97 | 1 | 98 | 90 | -8 | 9 |
| 2 | 107 | 113 | 6 | 91 | 86 | -5 | 11 |
| 9 | 83 | 102 | 19 | 87 | 91 | 4 | 15 |
| Av. | 91·5 | 94·6 | 3·0 | 91·2 | 97·5 | 6·2 | -3·1 |
| M | 2 | 5 | -3 | ||||
| 75%ile | 6 | 13·75 | 4·5 | ||||
| 25%ile | -·75 | -4·25 | -12 | ||||
| Q | 3·37 | 9·00 | 8·25 | ||||
| P. E. (distribution) | 2·09 | 8·24 | 8·86 | ||||
| P. E. (average) | ±·45 | ±1·79 | ±1·84 | ||||
| Av.=-1·71 P. E. | |||||||
| M.=-1·63 P. E. | |||||||
| Lost in 2nd period | Gained in 2nd period | No change | Gained equally with gain in 1st period | |
| Test group | 9 | 11 | 1 | 9 |
| Control group | 10 | 11 | 8 |
The average gain of the test group was 3·09 points after 12 months, compared with 2·25 after six. The control group, however, made an average gain of 6·24 after 12 months, the gain after six months being 3·29. These numbers are insignificant as gains, but they at least show no improvement in the test group which the control group does not reveal as well. On the basis of the results, we may say that there has been no improvement in I.Q. as a result of operation, either after six months or after twelve.
There remains to be considered only the result of the Healy Picture Completion Test. We have scores in this test for 18 pairs of cases. When these scores are compared with those in the former tests, the results stand as follows:
| Average of gains of test group in excess of control | -5·85 | -3·36 |
| Median of gains of test group in excess of control | -7·75 | 1·00 |
| P. E. of difference | ±3·05 | ±3·38 |
| Average in terms of P. E. | -1·92 | -·87 |
| Median in terms of P. E. | -2·54 | ·26 |
The figures given above show no gain in the Healy test as a result of operation. Both after six months, and after twelve, we find that the test group has gained no more than the control group. As before there are individual cases showing considerable gain in the second period, but these are matched by control cases which reveal equal or even greater gains. In the test group, 5 cases lost in the second period in comparison with the first, 18 gained, and 7 gained as much in the second period as in the first. The control group lost in the second period in 5 cases, gained in 18, and gained as much as in the first period in 7 cases. The two groups, then, are practically equal, both showing a gain in the second period, but this gain cannot be due to the operations, since the control group did not undergo operation.
TABLE XXII
Healy A, Second Retests, 18 Pairs
| N[16] | Test Group (A) | Control Group (B) | ||||||
| Test 1 | Test 3 | Gain | Test 1 | Test 3 | Gain | A-B | ||
| 12 | 20 | 1 | -19 | -10 | 41.5 | 51·5 | -70·5 | |
| 23 | 49·5 | 62·5 | 13 | 4 | 64 | 60 | -47 | |
| 15 | 7 | 19 | 12 | 1 | 54·5 | 53·5 | -41·5 | |
| 1 | -22 | 11 | 36 | -50 | 11 | 61 | -25 | |
| 2 | 28·5 | 24·5 | -4 | 3 | 19·5 | 16·5 | -20·5 | |
| 3 | 21·5 | 15·5 | -6 | 17 | 25·5 | 8·5 | -14·5 | |
| 19 | 57·5 | 60·5 | 3 | -22 | -15 | 7 | -4 | |
| 13 | 43 | 62·5 | 19·5 | -1·5 | 21·5 | 23 | -3·5 | |
| 21 | 20 | 38 | 18 | 70·5 | 88 | 17·5 | ·5 | |
| 10 | -12 | 11 | 23 | 27 | 48·5 | 21·5 | 1·5 | |
| 14 | 12·5 | 77 | 64·5 | -5 | 48·5 | 53·5 | 11 | |
| 27 | -25 | 25·5 | 50·5 | 2 | 39·5 | 37·5 | 13 | |
| 11 | -8 | 15·5 | 23·5 | -29 | -20 | 9 | 14·5 | |
| 16 | 49 | 79 | 30 | 30 | 45·5 | 15·5 | 14·5 | |
| 7 | -6 | 16 | 22 | 45 | 11 | 6·5 | 15·5 | |
| 28 | 29·5 | 77·5 | 48 | 64·5 | 83·5 | 19 | 29 | |
| 18 | -13·5 | 13·5 | 27 | -32 | -35 | -3 | 30 | |
| 20 | 0 | 55 | 55 | 30 | 48·5 | 18·5 | 36·5 | |
| Av. | 13·81 | 36·92 | 23·11 | 5·77 | 32·25 | 26·47 | -3·36 | |
| M | 22·5 | 18·75 | 1 | |||||
| 75%ile | 33 | 44 | 14·5 | |||||
| 25%ile | 7·5 | 8·75 | -22·25 | |||||
| Q | 12·75 | 17·62 | 18·37 | |||||
| P. E. (distribution) | 11·5 | 17·72 | 17·86 | |||||
| P. E. (average) | ±2·7 | ±4·22 | ±3·88 | |||||
| Av.=-·87 P. E. | ||||||||
| M.=+·26 P. E. | ||||||||