of work after 24 hours the effect of the later repetitions gradually decreases.
Series of 12 syllables (six of the series were each time combined into a test) were studied to the point of first possible reproduction; and immediately after the errorless reproduction each series was repeated three times (in all four times) as often as the memorisation (exclusive of the recital) had required. After 24 hours the same series were relearned to the first possible reproduction. Four tests furnished the following results (the numbers indicate the repetitions):
| Repetitions for the learning and recital of 6 series |
Immediately successive repetitions for the sake of greater surety |
Total number of repetitions used for the 6 series |
After 24 hours the memorization of the series required |
Thus the work saved by the total number of repetitions amounted to |
| 104 | 294 | 398 | 41 | 63 |
| 101 | 285 | 386 | 39 | 62 |
| 114 | 324 | 438 | 46 | 68 |
| 109 | 309 | 418 | 38 | 71 |
| m=107 | 303 | 410 | 41 | 66 P.E.m=1.4 |
In my own case—within reasonable limits—the after-effect of the repetitions of series of 12 syllables after 24 hours is a little smaller than is the case with 16 syllables; it must be estimated as at least three tenths of the sum total of the repetitions. If this relation were approximately to continue to hold with very numerous repetitions, it would be reasonable to expect that, after 24 hours, series on whose impression four times as many repetitions had been expended as were necessary for their first reproduction could be recited without any further expenditure of energy. Instead of this, in the cases examined, the relearning required about 35 per cent of the work required for the first recital. The effect of an average number of 410 repetitions was a saving of only one sixth of this sum. If now the first repetitions were represented by about three tenths of their amount, the effect of the later repetitions must have been very slight.
Investigation of the following kind, which I do not here give in detail, led to the same result. Syllable series of different
