SUMMARY FROM TABLE IV. N. O. V. M. _M._ 81 per cent. 73 per cent. 56 per cent. 69 per cent. _Mo._ 31 " 46 " 40 " 93 " _S._ 14 " 63 " 40 " 60 " _Hu._ 50 " 75 " 29 " 92 " _B._ 69 " 88 " 56 " 88 " _Ho._ 58 " 92 " 50 " 85 " ----------- ----------- ----------- ----------- Av. 51 per cent. 73 per cent. 45 per cent. 81 per cent. Av. gain in object couplets, 22 per cent. " " " movement couplets, 36 per cent. Before asking whether the results of the _C_ set confirm the conclusions already reached, we must compare the conditions of the three sets to see whether the changes in the conditions in the _C_ set have rendered it incomparable with the other two. The first change was the substitution of dissyllabic words in the verb and the movement series in the place of monosyllabic words. Since the change was made in both the verb and the movement series their comparability with each other is not interfered with, and this is the point at issue. Preliminary tests, however, made it highly probable that simple concrete dissyllabic words are not more difficult than monosyllabic in 5 secs. exposure. This change is therefore disregarded. The first important change introduced in the _C_ set was the reduction of the intervals between the tests for four subjects. The second was the lengthening of the exposure from 3 to 5 secs. These changes also do not lessen the comparability of the noun, object, verb and movement series with one another, since they affected all series of the _C_ set. The third change in the conditions was the substitution in the movement series of movements employing objects for movements of the body alone, and the consequent placing of objects on the table in the movement and in the object series of which the subject obtained a single mental image. All of the subjects were of the opinion that this single mental image was an aid in recall. Each of the objects contributing to form it was individualized by its spatial order among the objects on the table. The objects shown through the aperture were connected merely by temporal contiguity. On this account the object and the movement series of the _C_ set are not altogether comparable with those of the _A_ and the _B_ sets. We should expect _a priori_ that the object and the movement series in the _C_ set would be much better recalled than those of the _A_ and the _B_ sets.