TABLE I
| % of cards where certainty (1) appears in the attended-to group. | % of cards where certainty (1) appears elsewhere than in the attended-to group only. | % of cards where certainty (1) in attended-to group only. | % of cards where certainty (1) is stronger outside than within the attended-to group. |
| A 91% | 49% | 49% | 13.3% |
| B 97 | 91 | 83 | 28 |
| C 95 | 67 | 30 | 16.6 |
| D 93.3 | 69 | 24.5 | 11.2 |
| E 96.6 | 83.3 | 13.3 | 26.6 |
| F 88.8 | 30 | 53.3 | 8.3 |
| H 91.6 | 70 | 26.6 | 10 |
Table I answers the first part of our first problem promptly. Every subject gave judgments of the order certainty (1) about groups other than that attended to, in the case of a very considerable percentage of the cards. True, again in the case of a considerable (though generally smaller) percentage of those cards, each subject confined his judgments to the group attended to. The fact of individual variation stands out again here; and, moreover, the conclusions drawn should be qualified slightly because of the fact that it was often possible for the subjects to give all the letters and numerals on the cards, and still have, as it were, some attention left over for the other, supposedly non-attended-to groups. Such reaching beyond the properly attended-to group never seemed to be possible with either shapes or colors. Aside from this, however, it is clear that judgments of the highest grade of certainty were by no means limited to the group attended to.
This same table answers, also, the second part of the problem. Each subject found certainty of the highest grade sometimes stronger outside than within the group which held his attention. It is, of course, practically impossible to make absolutely certain that each subject's attention was invariably held to the group toward which it was turned, yet the percentage where certainty was stronger outside than within such groups seems large enough, in some cases, at least, as with subjects A, B, and H, to warrant our answering this second part of the problem in the negative. I should feel, however, that this was answered less definitely than was the first part of the problem. We may say, then, that the judgments made with the highest degree of certainty about a visual field will not be confined to the group attended to, and that we have strong evidence pointing toward the belief that we cannot expect there will invariably be more of such judgments within the group attended to than outside it.
TABLE II
| Label 1: % of judgments of certainty (1) given to each group in phase I (or when shapes were attended to). | Label 2: % of judgments of certainty (1) given to each group in phase II (or when colors were attended to). | Label 3: % of judgments of certainty (1) given to each group in phase III (or when letters and numerals were attended to). | Label 4: % of judgments of certainty (1) given to each group in phase IV (or when the attention was equally distributed over all the groups) | |||
| 1 | 2 | 3 | 4 | |||
| Subject | Shapes | (a) | 94% | 38% | 18% | 31% |
| A | Colors | (b) | 5 | 61 | 20 | 59 |
| Letters and Numerals | (c) | 0 | 0 | 61 | 9 | |
| Subject | (a) | 48 | 39 | 21 | 33 | |
| B | (b) | 43 | 60 | 29 | 38 | |
| (c) | 8 | 0 | 51 | 28 | ||
| Subject | (a) | 88 | 15 | 26 | 34 | |
| C | (b) | 8 | 77 | 28 | 8 | |
| (c) | 5 | 7 | 47 | 58 | ||
| Subject | (a) | 60 | 13 | 11 | 40 | |
| D | (b) | 19 | 67 | 2 | 37 | |
| (c) | 19 | 19 | 86 | 23 | ||
| Subject | (a) | 51 | 15 | 0 | 37 | |
| E | (b) | 22 | 56 | 8 | 29 | |
| (c) | 26 | 28 | 91 | 34 | ||
| Subject | (a) | 66 | 12 | 0 | 50 | |
| F | (b) | 14 | 77 | 0 | 27 | |
| (c) | 19 | 10 | 100 | 23 | ||
| Subject | (a) | 43 | 21 | 7 | 24 | |
| H | (b) | 29 | 52 | 4 | 19 | |
| (c) | 27 | 26 | 88 | 57 |
The most interesting part of this division of the experiment is brought out in Table II in answer to the problem, "Will the place of voluntary attention materially alter the distribution of judgments of the highest order of certainty among the given groups?" In every case the percentage is affected, in most cases, greatly affected. Take the case of subject A, for instance. Although, when his attention is equally distributed over the field 59% of the judgments we consider were of colors, yet when his attention was fixed on shapes and on letters and numerals this fell to 5% and 20% respectively. When it was fixed on colors, it rose, indeed, only to 61%. When, however, subject A fixed his attention upon the letters and numerals, 61% of the judgments were confined to the group attended to,—the same percentage as when colors were the attended-to group,—although, when his attention was distributed over the whole field, the percentage of these judgments about the group of letters and numerals was 9% only. When shapes were attended to, the 31% of the fourth phase of the experiment rose to 94%,—almost all of the judgments of the highest grade of certainty that were given were judgments about shapes. A similar study of the results given in the table can be made for the other subjects. The degree of change varies with the subject and with the group, but always there is some change, and often a very marked one. In this experiment the place of voluntary attention clearly did alter, and alter materially, the proportion of judgments of the highest order of certainty made about any given group.
That, indeed, would seem to me to be the answer of this experiment to the question as to the effect of voluntary attention upon certainty in one's judgments. Every subject showed a tendency to have more certainty in those judgments which were made about that aspect of the field toward which his attention was directed. Yet, on the other hand, this was a tendency only, one not strong enough to make it possible to predict beforehand exactly how great a proportion of the judgments in which he had the highest degree of confidence would be limited to that field, or even to be sure in every case that the greater proportion of those judgments would be so limited. The place of voluntary attention has an influence upon the subject-matter of the judgments made with certainty about a visual field just seen, but an influence of varying and uncertain strength.