Section 32. Influence of the Length of the Series
If the results for the first and second days are examined, welcome, though not surprising, supplementary data on the relation of dependence presented in Chapter V is obtained. In the former chapter, it was shown that, as the length of the series increased, the number of repetitions requisite increased very rapidly. Here, the result is that the effect of this need of more numerous repetitions in the cases investigated consists not merely in making the series just reproducible, but also in the firmer establishment of the longer series. After an interval of 24 hours they could be relearned to the point of being just reproducible with a saving both absolutely and relatively greater than with the shorter series.
The following table makes this relation clear.
| Number of syllables in one series |
Number of repetitions for learning |
Saving in repetitions in relearning after 24 hours |
Saving in % of requirement for first learning | |||
| 12 | 16 | .5 | 5 | .5 | 33 | .3 |
| 24 | 44 | 21 | .5 | 48 | .9 | |
| 36 | 55 | 32 | 58 | .2 | ||
The saving in the case of the shortest of the series investigated is one third for the second learning as compared with the first; while with the longest series, it is six tenths. It can be said, therefore, that by being learned to the first possible reproduction the series of 36 syllables is approximately twice as firmly established as the series of 12 syllables.
In this there is nothing new. On the basis of the familiar experience that that which is learned with difficulty is better retained, it would have been safe to prophesy such an effect from the greater number of repetitions. That which probably would not have been anticipated and which also demands attention, is the more definite determination of this general relation. So far as the numbers go, they seem to show that, between the increase of the repetitions necessary for the first learning and the inner stability of the series effected by them, there is no proportionality. Neither the absolute nor the relative saving of work advances in the same way as the number of repetitions;
