1. 50 each
2. 45 "
3. 50 "
4. 55 "
5. 60 to 40
6. 50 each
7. 45 "
8. 40 "
9. 45 "
10. 50 "
11. 55 "
12. 60 "
13. 40 to 60
14. 50 each
15. 45 "
16. 40 "
17. 35 "
18. 40 "
19. 45 "
20. 50 "
21. 55 "
22. 60 "
23. 60 to 45
24. 50 each
25. 45 "
26. 50 "
27. 60 "
28. 55 "
29. 50 "
30. 45 to 60
The time of a single exposure—in this case two groups at once—was 3 sec. measured by a stop-watch. As to the arrangement of the balls, care was taken that they should not be massed in one place, but scattered somewhat homogeneously over the space within the frames. The illumination was daylight, so managed that shadows cast by the balls were reduced to a minimum. The observer sat close to the table with the groups directly in front of him. He either kept his eyes closed between experiments or held a small screen before them. Sometimes he merely turned away. The operator worked from the opposite side of the table, taking care to make the necessary noises as little suggestive as possible. The observers agreed that they were not consciously influenced by the manipulation.
The progress of these experiments disclosed an astonishing space-error. So far as was conveniently possible the usual technique of elimination was employed.
1. The Influence of Active Pressure.
In this study the groups were differentiated in this way: With one hand the observer rolled the balls of one group under his fingers, while the other group was presented to vision only. The method of observation consisted in rapidly and lightly rolling the balls under the fingers a few times and then surveying both groups visually for the remainder of the exposure, judgment being given on the visual number.
Evidently there is much that is rough about this procedure. Pressure and kinæsthetic factors are lumped off together; the length of the touch-stimulus was not exactly determined; and there is the possibility that the visual stimulation from the group touched is weakened. To be sure the method prevents any great difference in the latter respect; and if we are guarded in our interpretation, something of interest may be learned.
There appeared to be no convenient way to eliminate the space-error. The right hand was used with the right group and the left with the left. So here again interpretation must be circumspect.
TABLE VI
| A | B | C | |||||||
| 52 experiments with each subject | 260 experiments with one and 208 with the other subject | 145 experiments with one and 260 with the other subject | |||||||
| Touch | No touch | No tendency | Uneven | Even | No tendency | Weight | No weight | No tendency | |
| Subjects | 2 | 1 | 1 | 2 | |||||
| Av. % of difference in favor of | 7.6 | 10 | 1 | 2.4 | |||||
| SPACE-ERROR | |||||||||
| Right | Left | No tendency | Right | Left | No tendency | Right | Left | No tendency | |
| Subjects | 1 | 1 | 1 | 1 | 1 | 1 | |||
| Av. % of difference in favor of | 69.2 | 23 | 30.8 | 20.2 | 32 | 4.4 | |||