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.

The fourth change was from imaged or made movements of the body alone to imaged or made movements employing objects.  If, as the A and the B sets have already demonstrated, the presence of objects at all is an aid to recall, the movement series of the C set should show a greater gain over their corresponding verb series than the simple movements of the body in the A and the B sets showed over their corresponding verb series.  For, employing objects in movements is adding the aid of objects to whatever aid there is in making the movements.