Turning to the results, we consider the C set by itself with reference to the effect of the use of objects vs. images in general. The summary from Table IV. shows that under the conditions given, after intervals of from slightly less than one day to two days, five of the six subjects recall object couplets better than noun couplets. One subject, M recalls noun couplets better. It also shows that under the conditions and after the intervals mentioned all six subjects recall movement couplets better than verb couplets. In view of the small difference here and of his whole record, however, M is probably to be classed as indifferent in both substantive and action series.
Thus far recall after these longer intervals has not been discussed. The experiment was originally devised to test recall after two days only, but it was found that with two of the subjects, M and Mo, recall for greater intervals could be obtained with slight additional trouble. This was accordingly done in the B and C sets. The results of the four other subjects in the B set are not so satisfactory on this point, because not enough was recalled.
The most interesting fact which developed was an apparently slower rate of forgetting, in many cases, of the nouns and verbs than of the objects and movements. In the noun-object group of the B set it is noticeable in three out of the four possible subjects, viz., B, Ho, and Mo. M alone does not show it. The two other subjects, S and B, did not recall enough for a comparison. In the verb-movement group of the B set it is also marked in three out of the four possible subjects, viz., M, Ho, and Mo. B alone does not show it. It is also seen in the C set in the results of M and Mo, in both the noun-object and the verb-movement groups. With the four other subjects in the C set it could not be noticed, since the series ran their course in a day. In M (verb-movement group, C set) and Mo (noun-object group, C set) the originally higher object or movement curves actually fall below their corresponding noun or verb curves.
The results of the tests for recall after nine and sixteen days are summarized in the following tables. They should be compared with the recall of these same series after two days given in Tables II. and IV., nor should it be forgotten that all four types started with perfect immediate recall. The figures give per cents, correct after eliminating indirect-association couplets.
SHOWING RECALL AFTER NINE AND SIXTEEN DAYS.—SUMMARY FROM B SET.