SLOT MAZE A. By Hehman H.
Young, Ph.D., of Pennsylvania. University
The slot maze designed by the author employs the fundamental principles of the pencil and stylus mazes in such a manner as to set an interesting practical problem by such mechanical construction of the test that only one solution is actually possible. This is accomplished by cutting the pattern of the maze out of a panel and mounting it in such manner that the slot with all its blind alleys furnishes a free passage-way for the movement of a slider so constructed that it cannot be removed from the board except at the ends of the course.
This makes the
"fool
proof" and eliminates all An entire series of these tests is being devised and standardized. This article, as a preliminary statement, is confined to a report on the use of the first of the series, Slot Maze A, in testing 1304 children ranging in age from four to necessity
for
test
negative
practically
instructions.
nine.
The
accompanying diagram shows the pattern of the maze. unshaded strip between the parallel lines is the cut out part of the panel and consistutes a continuous slot from the point A to the point B. The blind alleys are equally continuous with the direct path. The slots are ^ of an inch wide and an inch apart. The entire board is nearly a foot square. The starting point is indicated on the diagram by the letter A and the end or goal by the letter B. A toy boy clown about 1| inches high is set in the slot at B as the objective for the goal. He stands with his back toward the starting point and faces the slot down which the slider will approach him. The slider carries on its top a toy shoe just large enough to be easily grasped by young children. The circles in the The
narrow
slots at A and above B enable the slider to be inserted or removed these points. When in use the circular opening at the starting point A is closed so the child cannot remove the slider by returning
at
to the
starting point. Method.
The test is
placed in front of the
child
so
that the
right side
of the
goal boy is toward the child. This position of the test makes the slot leading from the starting point A, point directly toward the child. The instructions to the child are: "See this boy? (Pointing to the boy). This (grasping the shoe) is his shoe. The boy wants (73)
74
THE PSYCHOLOGICAL CLINIC.
his shoe. I want you to take it to him. See how quickly you can take the shoe to the boy." (With these last instructions the shoe being firmly grasped by the examiner is slowly moved several inches the slot directly toward the child.) The above are the full set of exact instructions
along
given the child. they are not given verbatim, the examiner is apt to give the child a cue by unwittingly using the word around in some such statement as, "Push the shoe around to the boy." If
The time is counted in seconds from the instant the above instructions are completed until the child gets the shoe in the slot in front of and against the boy. If the child does not complete the test by the end of five minutes, his time record is marked DNC, and the test is stopped. Sometimes a child stops, thinking the test completed, when the shoe is in a slot opposite the goal boy, but not in the right one. When a child does this or gives up before the end of the five-minute time limit, he is urged to continue by repeating part or all, as the case may require, of the original instructions, as, "The boy wants his shoe. Take it to him." Only in rare instances is it necessary to give the additional urge, "Go on, put the shoe in the boy's hands." If the child says he cannot do it, he is encouragingly told, "Oh, yes you can. The other boys (or girls) did it and No other instructions, verbal or otherwise, are ever you can too."
given.
Encouragement,
but
no
assistance dare be
given,
because the
purpose of the test is to learn whether the child with the objective clearly defined can discover the route by which to deliver the shoe.
At the end of each trial the examiner lifts out the slider through the opening in front of the goal boy and inserts it at starting point A, ready for the next trial. Children who complete the test within the time limit are given a second trial immediately with instructions, "See if you can take it
(pointing to the shoe) kept and recorded as on
to him quicker this time." The time is Five minutes is the time the first trial.
limit here also. Type
and
Distribution
of
Children Tested.
The children tested for this report came from four schools in In one district, different districts of the City of Philadelphia.* children came from homes considered to be above average so far as A social status and type of occupation of parents is concerned. second district is rated below average in these same respects, while * Acknowledgements are due District Superintendent Dr. C. A. Coulomb, and to Principals M. L. Emrey and Charles Buckley, for opening their schools to this investigation, and to Mary H. Young and S. Sanderson, graduate students of the University of Pennsylvania, for assisting in testing children.
SLOT MAZE A.
Slot Maze A.
75
76
THE PSYCHOLOGICAL CLINIC.
the other two districts are rated as about average. In the first two schools every child up to and including 7 years and 11 months of age was tested. In one of the others every child up to and including 8 years and 11 months of age was tested, while in the fourth school children under 6 years of age
only
were
tested.
Results. Table I
gives the ten percentile distributions for boys and girls separately. Under age 4 are reported all children according to sex who at the time of examination were 4 years old but not 5. All age In Table I immediately groups are constructed on this same plan. under each age is given the number of children tested at that age. The best score of the poorest ten per cent of scores made on the first trial in each age is set down in the table opposite the 10th percentile. In the same way the remainder of the table shows the best score for every tenth
best
score
percentile.
Thus the 100th
percentile
line shows the
made at each age.
Table I.?First Trial Percentiles in Seconds Girls.
for
642 Boys and 662
Girls.
Boys.
Age. No. of Cases.
39
126
100
35
20
18
20
90
89
40
35
29
80
120
63
45
37
70 60
180
81
60 77 101
44
168
191
118
36
128
14
60
22
133
28 36
206
200
92
27
15 58
17 36
21
82
160
117
85
53
265
177
120
198
140
DNC DNC DNC DNC DNC DNC
225
78 110 146
Percents
188 DNC DNC DNC DNC DNC DNC
50 40
30 20 10 0
DNC 55 DNC 63 DNC 240 120 98 86 DNC 117 DNC 190 135 DNC DNC 300 169 260 DNC DNC DNC 300 DNC DNC DNC DNC DNC 120 170
54 75
43
DNC DNC DNC DNC DNC
35 45 59
77 105
215
131
295 DNC DNC DNC
210 275 DNC DNC
In every instance, except in the 100th percentile which is the best score and hence cannot be expected to be uniformly consistent, the time values for the older children are shorter than for any younger Six per cent of the eight-year-old age group within the same sex. and nine per cent of the seven-year-old boys did not complete the In all other ages the number test within the five-minute time limit. trial
of DNC's
was
greater than
ten per cent.
SLOT MAZE A.
Figure Figure
1. 1.
Percentiles of First Trial Time. Percentiles op Broken Line Girls.
77
Full Line Boys.
of the percentile distribution The numbers across the top indicate the ten percentile limits, and those at the side indicate the time in seconds. The As DNC number on each curve indicates the age it represents. it means that signifies an arbitrary time limit and is not a time value,
Figure
of Table I.
1 is
a
graphic representation
THE PSYCHOLOGICAL CLINIC.
78
the actual time for
the test, if sufficient time had been three hundred seconds for those allowed, scored DNC. Because the direction of the time curves beyond three hundred seconds is not known they stop just over the 300second line. This figure shows more clearly than Table I how within each
completing
would have been
over
the different age groups maintain their identity, never crossing approximating one another except at the 100th percentile. This is a convenient chart for comparing the time record of an individual child. His percentile rating can be determined by locating the level of his score on the left of the chart and following it in on This point of intersection a horizontal line to his sex and age group. can be read into a percentile by noting its position on one or relative position between two of the vertical ten percentile lines. sex
or even
Table II.?Second Trial
Quintiles
and
Medians
in
Seconds
for the
523 Boys and the 412 Girls who Completed First Trial. Girls.
Boys.
Age. No. of Cases.
19
85
136
172
111
13
62
120
143
74
Percents 100
21
17
13
13
12
30
21
12
14
14
80
37
26
22
20
16
51
36
27
24
22
60
79
39
30
24
19
62
58
36
30
28
50
90
48 70
36
26
21
162
88
52
34
40
40 20 0
24 30 40 51 131 91 182 DNC DNC DNC DNC 275 156
50
72 43 47 220 300 158 81 101 DNC DNC DNC DNC DNC 205
125
Table II is constructed for the second trial in the same manner Table I for the first trial, except that only the median and every twentieth instead of every tenth percentile are given. That there are fewer cases here is due to the fact that those who failed to complete the test on the first trial within the five-minute time limit did For the boys there is a consistent decrease in not get a second trial. time with increasing age, but for the girls this is not true. For the as
20th, 40th and 50th percentiles the time for eight-year-old girls is longer than for the seven-year-old girls. The eight-year-old boys constitute the only group where every child successfully completed Of the eightthe second trial within the five-minute time limit. year-old girls only one failed.
SLOT MAZE
Figure 2.
Medians
of op
First and Second Trials. Broken Line Girls.
79
Full Line Line Boys. Boys.
gives the medians for both sexes on both trials. Itrapid decrease in time which accompanies increasing age, especially on the first trial. The young children do the second trial so well that on it it would be impossible to have the same rate of improvement with increasing age. Table III is employed to show that on an average within certain Figure
2
shows the
limits there is
a direct ratio between rate on first trial and rate on second trial. The boys and girls are treated separately. The first column shows first trial time intervals, the second column the number of boys who completed their first trial within the time interval of the first column, the third column gives the median time for these
same
boys
on
their second
trial,
and the fourth column
gives
the
80
THE PSYCHOLOGICAL CLINIC.
Table III.?Second Trial Median Time Values as Related to Time on First Trial for the 523 Boys and the 412 Girls who Completed First Trial. Girls.
Boys. First Trial, Seconds.
of Cases.
of Cases.
M.
P. E.
3
20
16
21
? 4.5 5.5 3 5.5 19
No.
No.
M.
P. E.
13
32
20- 29.
53
18
3040506070-
39.
52
22
0.5 2.5 3.5
49.
25
9
26
8.5
69.
72 38 35
30
22
26 27
10- 19.
79.
33
33
12
18
23 25 26 35 50
80- 99.
45
33
34
44
100-119. 120-139. 140-159. 160-179. 180-199. 200-249. 250-300.
43
41
64
26
50 57
18 37 26
41
89
22
33 43
15
79 65 81
27 47 83 46
24
25
36
40
46 69 125 55 70
59.
26 30
30
24
28 32
19
34 38 53 70 65 84 54
48
probable error of this median. The P. E. here is one-half the difThus the figures ference between the upper and lower quartiles. in the first line of the table mean that eight boys finished their first trial somewhere in the time interval between ten and nineteen seconds, and that the median time for these same boys on their second trial was thirteen seconds with a probable error of 0.5 seconds. The last three columns of the table give the same information about the girls as columns 2, 3 and 4 do for the boys. The second trial probable errors are very much smaller for those children who completed the first trial in less than one minute, than for those children consuming more than a minute on their first trial. Second trial times vary directly with first trial times up to one minute, but beyond this the second trial medians are much longer and do not show any consistent relationship to first trial times. No child who completed the first trial in less than forty-five seconds failed the second trial. Only three children of those completing first trial under one minute failed second trial. Sex Differences.
Probably the consistently large sex differences were the most unexpected result obtained in this investigation. The first trial median times for the girls of every age are approximately twice as
SLOT MAZE A.
81
large
There is considerable as those for the boys of the same age. variation on the second trial medians, the least sex difference coming at seven years of age where the median for the girls is only 31 per cent above that for the boys. Letting 100 per cent represent the median time for boys at each age, the percentage values of the median times for girls at the various ages are as follows: 5
4
Age First trial..
?
Second trial
180
6
7
8
177+(?)
223
195
192
183
144
131
190
Considering the number of children failing to complete the test within the five-minute time limit, the percentage of failures is as follows: 19 per cent of the 38 per cent of the and of those
completing
boys failed on the first trial, girls failed on the first trial,
the first
3.4 per cent of the 6.3 per cent of the
trial,
boys failed on the second trial, girls failed on the second trial.
and
These differences are graphically represented on Figures 1 and 2, and by the blocks of DNC in Table I. Figure 1 also shows how nearly identical throughout are the time values for the four-year-old boys and the five-year-old girls, and also those for the six-year-old boys and the eight-year-old girls. Discussion. As it is the purpose of this article only to introduce the slot maze and furnish a preliminary standardization of slot maze A, no attempt is made to analyze the various mental and physical factors involved in its performance or to give an interpretation of the sex differences revealed. After testing several hundred children it was decided that slot maze A would hardly be of value as a test for children nine years of age and older. Accordingly only children under nine were taken for this investigation. The distribution tables indicate that
boys at least one year older and that years older should have been included.
girls
two and
possibly
three
There are great differences in the time taken by children of the age in performing this test and there is much overlapping in the successive ages. These variations and overlappings, however, are probably no greater than the variations and overlappings in same
mental make-up of the children. These differences and overlappings in a test make it distinctly useful to bring out individual differences,
82
THE PSYCHOLOGICAL CLINIC.
but
seemingly do not enable the validity of the differences it reveals satisfactorily established by statistical treatment.* As a test free from the classical fitting together of blocks in one form or another, the slot maze fills a gap in the array of clinical tests. Slot maze A is useful in testing children four to ten years of age. The time required for the performance of the test by children of these ages is sufficiently long to allow ample time for the examiner to make significant qualitative observations of the child's behavior in addition to getting his reaction time. The average decrease in to be
time of the second trial over the first is not the result of increased efficiency in the physical manipulation of the test. It is the average time required by the children to learn how to solve the problem of delivering the shoe. * S. W. Fernberger, "Statistical logical Clinic, 1922, XIV, 68.
vs.
Non-Statistical Interpretation of Test Results," Psycho-
Young, Ph.D., of Pennsylvania. University
The slot maze designed by the author employs the fundamental principles of the pencil and stylus mazes in such a manner as to set an interesting practical problem by such mechanical construction of the test that only one solution is actually possible. This is accomplished by cutting the pattern of the maze out of a panel and mounting it in such manner that the slot with all its blind alleys furnishes a free passage-way for the movement of a slider so constructed that it cannot be removed from the board except at the ends of the course.
This makes the
"fool
proof" and eliminates all An entire series of these tests is being devised and standardized. This article, as a preliminary statement, is confined to a report on the use of the first of the series, Slot Maze A, in testing 1304 children ranging in age from four to necessity
for
test
negative
practically
instructions.
nine.
The
accompanying diagram shows the pattern of the maze. unshaded strip between the parallel lines is the cut out part of the panel and consistutes a continuous slot from the point A to the point B. The blind alleys are equally continuous with the direct path. The slots are ^ of an inch wide and an inch apart. The entire board is nearly a foot square. The starting point is indicated on the diagram by the letter A and the end or goal by the letter B. A toy boy clown about 1| inches high is set in the slot at B as the objective for the goal. He stands with his back toward the starting point and faces the slot down which the slider will approach him. The slider carries on its top a toy shoe just large enough to be easily grasped by young children. The circles in the The
narrow
slots at A and above B enable the slider to be inserted or removed these points. When in use the circular opening at the starting point A is closed so the child cannot remove the slider by returning
at
to the
starting point. Method.
The test is
placed in front of the
child
so
that the
right side
of the
goal boy is toward the child. This position of the test makes the slot leading from the starting point A, point directly toward the child. The instructions to the child are: "See this boy? (Pointing to the boy). This (grasping the shoe) is his shoe. The boy wants (73)
74
THE PSYCHOLOGICAL CLINIC.
his shoe. I want you to take it to him. See how quickly you can take the shoe to the boy." (With these last instructions the shoe being firmly grasped by the examiner is slowly moved several inches the slot directly toward the child.) The above are the full set of exact instructions
along
given the child. they are not given verbatim, the examiner is apt to give the child a cue by unwittingly using the word around in some such statement as, "Push the shoe around to the boy." If
The time is counted in seconds from the instant the above instructions are completed until the child gets the shoe in the slot in front of and against the boy. If the child does not complete the test by the end of five minutes, his time record is marked DNC, and the test is stopped. Sometimes a child stops, thinking the test completed, when the shoe is in a slot opposite the goal boy, but not in the right one. When a child does this or gives up before the end of the five-minute time limit, he is urged to continue by repeating part or all, as the case may require, of the original instructions, as, "The boy wants his shoe. Take it to him." Only in rare instances is it necessary to give the additional urge, "Go on, put the shoe in the boy's hands." If the child says he cannot do it, he is encouragingly told, "Oh, yes you can. The other boys (or girls) did it and No other instructions, verbal or otherwise, are ever you can too."
given.
Encouragement,
but
no
assistance dare be
given,
because the
purpose of the test is to learn whether the child with the objective clearly defined can discover the route by which to deliver the shoe.
At the end of each trial the examiner lifts out the slider through the opening in front of the goal boy and inserts it at starting point A, ready for the next trial. Children who complete the test within the time limit are given a second trial immediately with instructions, "See if you can take it
(pointing to the shoe) kept and recorded as on
to him quicker this time." The time is Five minutes is the time the first trial.
limit here also. Type
and
Distribution
of
Children Tested.
The children tested for this report came from four schools in In one district, different districts of the City of Philadelphia.* children came from homes considered to be above average so far as A social status and type of occupation of parents is concerned. second district is rated below average in these same respects, while * Acknowledgements are due District Superintendent Dr. C. A. Coulomb, and to Principals M. L. Emrey and Charles Buckley, for opening their schools to this investigation, and to Mary H. Young and S. Sanderson, graduate students of the University of Pennsylvania, for assisting in testing children.
SLOT MAZE A.
Slot Maze A.
75
76
THE PSYCHOLOGICAL CLINIC.
the other two districts are rated as about average. In the first two schools every child up to and including 7 years and 11 months of age was tested. In one of the others every child up to and including 8 years and 11 months of age was tested, while in the fourth school children under 6 years of age
only
were
tested.
Results. Table I
gives the ten percentile distributions for boys and girls separately. Under age 4 are reported all children according to sex who at the time of examination were 4 years old but not 5. All age In Table I immediately groups are constructed on this same plan. under each age is given the number of children tested at that age. The best score of the poorest ten per cent of scores made on the first trial in each age is set down in the table opposite the 10th percentile. In the same way the remainder of the table shows the best score for every tenth
best
score
percentile.
Thus the 100th
percentile
line shows the
made at each age.
Table I.?First Trial Percentiles in Seconds Girls.
for
642 Boys and 662
Girls.
Boys.
Age. No. of Cases.
39
126
100
35
20
18
20
90
89
40
35
29
80
120
63
45
37
70 60
180
81
60 77 101
44
168
191
118
36
128
14
60
22
133
28 36
206
200
92
27
15 58
17 36
21
82
160
117
85
53
265
177
120
198
140
DNC DNC DNC DNC DNC DNC
225
78 110 146
Percents
188 DNC DNC DNC DNC DNC DNC
50 40
30 20 10 0
DNC 55 DNC 63 DNC 240 120 98 86 DNC 117 DNC 190 135 DNC DNC 300 169 260 DNC DNC DNC 300 DNC DNC DNC DNC DNC 120 170
54 75
43
DNC DNC DNC DNC DNC
35 45 59
77 105
215
131
295 DNC DNC DNC
210 275 DNC DNC
In every instance, except in the 100th percentile which is the best score and hence cannot be expected to be uniformly consistent, the time values for the older children are shorter than for any younger Six per cent of the eight-year-old age group within the same sex. and nine per cent of the seven-year-old boys did not complete the In all other ages the number test within the five-minute time limit. trial
of DNC's
was
greater than
ten per cent.
SLOT MAZE A.
Figure Figure
1. 1.
Percentiles of First Trial Time. Percentiles op Broken Line Girls.
77
Full Line Boys.
of the percentile distribution The numbers across the top indicate the ten percentile limits, and those at the side indicate the time in seconds. The As DNC number on each curve indicates the age it represents. it means that signifies an arbitrary time limit and is not a time value,
Figure
of Table I.
1 is
a
graphic representation
THE PSYCHOLOGICAL CLINIC.
78
the actual time for
the test, if sufficient time had been three hundred seconds for those allowed, scored DNC. Because the direction of the time curves beyond three hundred seconds is not known they stop just over the 300second line. This figure shows more clearly than Table I how within each
completing
would have been
over
the different age groups maintain their identity, never crossing approximating one another except at the 100th percentile. This is a convenient chart for comparing the time record of an individual child. His percentile rating can be determined by locating the level of his score on the left of the chart and following it in on This point of intersection a horizontal line to his sex and age group. can be read into a percentile by noting its position on one or relative position between two of the vertical ten percentile lines. sex
or even
Table II.?Second Trial
Quintiles
and
Medians
in
Seconds
for the
523 Boys and the 412 Girls who Completed First Trial. Girls.
Boys.
Age. No. of Cases.
19
85
136
172
111
13
62
120
143
74
Percents 100
21
17
13
13
12
30
21
12
14
14
80
37
26
22
20
16
51
36
27
24
22
60
79
39
30
24
19
62
58
36
30
28
50
90
48 70
36
26
21
162
88
52
34
40
40 20 0
24 30 40 51 131 91 182 DNC DNC DNC DNC 275 156
50
72 43 47 220 300 158 81 101 DNC DNC DNC DNC DNC 205
125
Table II is constructed for the second trial in the same manner Table I for the first trial, except that only the median and every twentieth instead of every tenth percentile are given. That there are fewer cases here is due to the fact that those who failed to complete the test on the first trial within the five-minute time limit did For the boys there is a consistent decrease in not get a second trial. time with increasing age, but for the girls this is not true. For the as
20th, 40th and 50th percentiles the time for eight-year-old girls is longer than for the seven-year-old girls. The eight-year-old boys constitute the only group where every child successfully completed Of the eightthe second trial within the five-minute time limit. year-old girls only one failed.
SLOT MAZE
Figure 2.
Medians
of op
First and Second Trials. Broken Line Girls.
79
Full Line Line Boys. Boys.
gives the medians for both sexes on both trials. Itrapid decrease in time which accompanies increasing age, especially on the first trial. The young children do the second trial so well that on it it would be impossible to have the same rate of improvement with increasing age. Table III is employed to show that on an average within certain Figure
2
shows the
limits there is
a direct ratio between rate on first trial and rate on second trial. The boys and girls are treated separately. The first column shows first trial time intervals, the second column the number of boys who completed their first trial within the time interval of the first column, the third column gives the median time for these
same
boys
on
their second
trial,
and the fourth column
gives
the
80
THE PSYCHOLOGICAL CLINIC.
Table III.?Second Trial Median Time Values as Related to Time on First Trial for the 523 Boys and the 412 Girls who Completed First Trial. Girls.
Boys. First Trial, Seconds.
of Cases.
of Cases.
M.
P. E.
3
20
16
21
? 4.5 5.5 3 5.5 19
No.
No.
M.
P. E.
13
32
20- 29.
53
18
3040506070-
39.
52
22
0.5 2.5 3.5
49.
25
9
26
8.5
69.
72 38 35
30
22
26 27
10- 19.
79.
33
33
12
18
23 25 26 35 50
80- 99.
45
33
34
44
100-119. 120-139. 140-159. 160-179. 180-199. 200-249. 250-300.
43
41
64
26
50 57
18 37 26
41
89
22
33 43
15
79 65 81
27 47 83 46
24
25
36
40
46 69 125 55 70
59.
26 30
30
24
28 32
19
34 38 53 70 65 84 54
48
probable error of this median. The P. E. here is one-half the difThus the figures ference between the upper and lower quartiles. in the first line of the table mean that eight boys finished their first trial somewhere in the time interval between ten and nineteen seconds, and that the median time for these same boys on their second trial was thirteen seconds with a probable error of 0.5 seconds. The last three columns of the table give the same information about the girls as columns 2, 3 and 4 do for the boys. The second trial probable errors are very much smaller for those children who completed the first trial in less than one minute, than for those children consuming more than a minute on their first trial. Second trial times vary directly with first trial times up to one minute, but beyond this the second trial medians are much longer and do not show any consistent relationship to first trial times. No child who completed the first trial in less than forty-five seconds failed the second trial. Only three children of those completing first trial under one minute failed second trial. Sex Differences.
Probably the consistently large sex differences were the most unexpected result obtained in this investigation. The first trial median times for the girls of every age are approximately twice as
SLOT MAZE A.
81
large
There is considerable as those for the boys of the same age. variation on the second trial medians, the least sex difference coming at seven years of age where the median for the girls is only 31 per cent above that for the boys. Letting 100 per cent represent the median time for boys at each age, the percentage values of the median times for girls at the various ages are as follows: 5
4
Age First trial..
?
Second trial
180
6
7
8
177+(?)
223
195
192
183
144
131
190
Considering the number of children failing to complete the test within the five-minute time limit, the percentage of failures is as follows: 19 per cent of the 38 per cent of the and of those
completing
boys failed on the first trial, girls failed on the first trial,
the first
3.4 per cent of the 6.3 per cent of the
trial,
boys failed on the second trial, girls failed on the second trial.
and
These differences are graphically represented on Figures 1 and 2, and by the blocks of DNC in Table I. Figure 1 also shows how nearly identical throughout are the time values for the four-year-old boys and the five-year-old girls, and also those for the six-year-old boys and the eight-year-old girls. Discussion. As it is the purpose of this article only to introduce the slot maze and furnish a preliminary standardization of slot maze A, no attempt is made to analyze the various mental and physical factors involved in its performance or to give an interpretation of the sex differences revealed. After testing several hundred children it was decided that slot maze A would hardly be of value as a test for children nine years of age and older. Accordingly only children under nine were taken for this investigation. The distribution tables indicate that
boys at least one year older and that years older should have been included.
girls
two and
possibly
three
There are great differences in the time taken by children of the age in performing this test and there is much overlapping in the successive ages. These variations and overlappings, however, are probably no greater than the variations and overlappings in same
mental make-up of the children. These differences and overlappings in a test make it distinctly useful to bring out individual differences,
82
THE PSYCHOLOGICAL CLINIC.
but
seemingly do not enable the validity of the differences it reveals satisfactorily established by statistical treatment.* As a test free from the classical fitting together of blocks in one form or another, the slot maze fills a gap in the array of clinical tests. Slot maze A is useful in testing children four to ten years of age. The time required for the performance of the test by children of these ages is sufficiently long to allow ample time for the examiner to make significant qualitative observations of the child's behavior in addition to getting his reaction time. The average decrease in to be
time of the second trial over the first is not the result of increased efficiency in the physical manipulation of the test. It is the average time required by the children to learn how to solve the problem of delivering the shoe. * S. W. Fernberger, "Statistical logical Clinic, 1922, XIV, 68.
vs.
Non-Statistical Interpretation of Test Results," Psycho-
