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.
[15]: A. H. MacPhail, Adenoids and Tonsils: A study showing
how the Removal of Enlarged or Diseased Tonsils Affects a Child's
Work in School. Ped. Sem., June, 1920, pp. 188-194.
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 49.7 13 18
1C 15 53.5 62.8 46.4 49.7 11 15
2 15 40.9 47.9 42.6 45.9 9 10
2C 17 52.3 65.5 45.2 49.8 10 15
3 16 55 67.5 47 50.2 12.8 13
3C 14 61.5 57.8 51.7 54 14 14.5
4 13 51.1 60.2 47.5 50.5 9
4C 13 49.4 54.2 48.9 50.8 9.5
7 14 39.9 45.8 42.9 45.6 7 6
7C 12 38.4 42.1 41.9 43.7 9 14
8 11 60.8 69.2 50.8 52.3 10
8C 11 45.4 57.9 36.8 48.7 15
10 11 48.9 56.7 46.1 48.6 12.5 12
10C 11 47.1 51.8 45.6 48.1 10 12
11 12 47.8 55 45.8 49.5 11 11
11C 12 41.6 47 43.6 46.8 11.5 7.5
12 12 48 66.5 44.8 14
12C 11 41 69.6 41.5 6
13 12 90 112 61.3 61.8 26.5 28.5
13C 12 74.7 88 56.8 60.0 22 27
14 12 56 66 51 53.3 16 17
14C 12 81.9 98 57.9 59.5 22 22.5
15 12 57.5 51.1 15.5
15C 10 67.2 50.1 15
16 12 56 60.3 51.6 53.5 19 18.5
16C 11 51.2 55 48.7 50.1 10 10
18 12 58.2 47.3 18
18C 11 45.3 46.7 8
19 12 90 108 57.7 60.5 22 20
19C 11 52.4 59 46.7 48 15 18
20 12 44.2 47.2 11
20C 11 61.3 49.6 15
21 12 70.7 85.5 54.1 16.5 15
21C 10 62.4 69.2 49.6 19 17
23 12 51.7 47.8 11.5 15
23C 11 64.1 51.4 14.5 16
27 12 43.7 45.4 9 6
27C 11 41 44.6 8 9
28 12 71.3 78.5 54.9 56.3 23.5
28C 11 74.2 85.8 53.4 55.9 21
TABLE XIV (Continued)
N[16] Tapping I.Q. Healy
Test 1 Test 3 (1) (3) (1) (3)
1 135 142 82 93 -25 11
1C 106 134 80 85 -50 11
2 105 135 107 113 28.5 24.5
2C 152 139 91 86 3 19.5
3 136 144 94 91 21.5 15.5
3C 135 135 82 96 17 25.5
4 103 96 111 8.5
4C 109 83 102 33
7 125 91 93 - 6 16
7C 105 95 112 4.5 11
8 113 128 91 92 32.5
8C 131 121 98 111 4
10 68+ 74 145+106 110 116 -12 11
10C 70+ 74 148+124 104 107 27 48.5
11 125+ 90 120+125 103 102 - 8 15.5
11C 155+125 102+112 101 95 -29 -20
12 98+ 69 98 86 20 1
12C 102 98 90 -10 41.5
13 160+165 176+187 70 61 43 62.5
13C 150+109 188+174 66 60 -1.5 21.5
14 190+172 228+215 96 102 12.5 77
14C 175+152 165+186 140 138 - 5 48.5
15 172+167 192+186 97 97 7 19
15C 140+115 145+133 78 98 1 54.5
16 145+131 65 74 49 79
16C 145+ 99 74 81 30 45.5
18 133+115 126+145 98 101 -13.5 13.5
18C 100+ 99 108+ 92 90 92 -32 -35
19 168+136 96 97 57.5 60.5
19C 100+115 98 90 -22 -15
20 105+115 122+118 106 116 0 55
20C 150+120 154+154 118 140 30 48.5
21 152+111 154+155 64 66 20 38
21C 140+136 174+150 86 93 70.5 88
23 150+119 157+157 85 80 49.5 62.5
23C 122+115 141+141 81 88 4 64
27 108+ 92 114+ 95 110 112 -25 25.5
27C 115+105 101+118 72 98 2 39.5
28 150+148 176+168 81 83 29.5 77.5
28C 178+148 172+157 95 94 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 41 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 1.9
Median 1.2 2.2
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 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 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 53.3 2.3 57.9 59.5 1.6 .7
3 47 50.2 3.2 51.7 54 2.3 .9
7 42.9 45.6 2.7 41.9 43.7 1.8 .9
4 47.5 50.5 3 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 .2 .5
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
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 0 - .5
3 12.5 13 .5 14 14.5 .5 0
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 0 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 12
months 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 11
P. E. of difference +-3.10 +- 5.26
Average in terms of P. E. .03 1.89
Median in terms of P. E. 0 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 - .06
Median of gains of test group in excess of control -.015 - .09
P. E. of difference +-.04 +- .036
Average in terms of P. E. -.50 -1.66
Median in terms of P. E. -.38 -2.50
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 12
months 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 0 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 Gained in 2nd No Gained equally
period period change 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
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.
TABLE XXIII
Weight in Height in Height-weight Grip in
Gains pounds inches percents Kg.
lb. P. E. in. P. E. % P. E. Kg. P. E.
Av. 1 1.37 2.85 .16 1. 1.83 2.02 - .24 - .50
Av. 2 1.90 1.30 .08 .29 3.23 2.81 -1.31 -2.22
M. 1 1.20 2.80 .20 1.25 4.00 4.40 -1.00 -2.08
M. 2 2.20 1.51 .50 1.79 6.00 5.22 -1.50 -2.54
P. E. 1 +- .48 +-.16 +-.91 +-.48
P. E. 2 +-1.46 +-.28 +-1.15 +-.59
Gains Taps in Tapping in
1/2 min. fatigue ratios I.Q. Healy Score
taps P. E. ratio P. E. Pts. P. E. Pts. P. E.
Av. 1 .09 .03 -.02 - .50 -1.035 - .94 -5.85 - .92
Av. 2 9.93 1.89 -.065 -1.66 -3.14 -1.71 -3.36 - .87
M. 1 0. 0. -.015 - .38 -1. - .99 -7.75 -2.54
M. 2 11. 2.09 -.09 -2.50 -3. -1.63 1 .26
P. E. 1 +-3.10 +-.04 +-1.10 +-3.05
P. E. 2 +-5.26 +-.036 +-1.84 +-3.88
In Table XXIII are collected the results discussed in the foregoing
chapter. The mean results are expressed in terms of P. E. and as gross
values, so that the various tests may be compared.