Page:Memory (1913).djvu/64

this time can be learned from the tests themselves. For, in their case, the number of repetitions is greater than the average minimum for the first possible reproduction, which in the case of the 16-syllable series (p. 46) amounted to 31 repetitions. In their case, therefore, the point can be determined at which the first errorless reproduction of that series appeared as the number of repetitions kept on increasing. But on account of the continued increase in the number of repetitions and the resulting extension of the time of the test, the conditions were somewhat different from those in the customary learning of series not hitherto studied. In the case of the series to which a smaller number of repetitions than the above were given, the numbers necessary for comparison cannot be derived from their own records, since, as a part of the plan of the experiment, they were not completely learned by heart. I have consequently preferred each time to find the saving of work in question by comparison with the time required for learning by heart not the same but a similar series up to that time unknown. For this I possess a fairly correct numerical value from the time of the tests in question: any six 16-syllable series was learned, as an average of 53 tests, in 1,270 seconds, with the small probable error ± 7.

If all the mean values are brought together in relation to this last value, the following table results:

I After a preceding study of the series by X repetitions,	II They were just memorized 24 hours later in Y seconds		III The result therefore of the preceding study was a saving of T seconds,		IV Or, for each of the repetitions, an average saving of D seconds
X=	Y=	P.E.m=	T=	P.E.m=	D=
0	1270	7
8	1167	14	103	16	12.9
16	1078	28	192	29	12.0
24	975	17	295	19	12.3
32	863	15	407	17	12.7
42	697	14	573	16	13.6
53	585	9	685	11	12.9
64	454	11	816	13	12.8
					m=	12.7