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. TABLE III 1 = % of mistakes in judgments of certainty (1). 2 = % of mistakes in judgments of certainty (2). 3 = % of mistakes in judgments of certainty (3). 4 = % of mistakes in judgments of certainty (4). x = no judgments of that kind given. 1 2 3 4 Subject A (in giving shapes) (a) 7% 10% 0% 100% (in giving colors) (b) 2 14 23 0 (in giving letters and numerals) (c) 0 0 x x Subject B (a) 2 10 10 0 (b) 3 6 20 25 (c) 4 50 0 x Subject C (a) 1 8 10 0 (b) 4 14 14 0 (c) 1 0 16 0 Subject D (a) 3 4 0 16 (b) 1 6 0 0 (c) 5 0 0 0 Subject E (a) 2 10 25 50 (b) 1 33 40 0 (c) 0 0 0 0 Subject F (a) 1 25 7 25 (b) 4 15 29 26 (c) 3 0 0 x Subject H (a) 3 6 5 0 (b) 6 2 15 15 (c) 4 0 0 20 TABLE IV Label 1: General % of mistakes in judgments of certainty (1). Label 2: % of mistakes in judgments of certainty (1) about attended-to groups.