from the former in that here the odd-numbered syllables of the original series were not followed by the even-numbered syllables of the same series. But all the odd-numbered syllables of two original series were united to form a new 16-syllable series. Then the even-numbered syllables of the same original series were united to form a second new series. The scheme of the derived series was therefore not, as above,
| I(1) | I(3) | I(5) | I(15) | I(2) | I(4) | I(16) | ||
| II(1) | II(3) | II(5) | II(15) | II(2) | II(4) | II(16) |
but rather
| I(1) | I(3) | I(5) | I(15) | I(1) | I(3) | I(15) | ||
| I(2) | I(4) | I(6) | I(16) | II(2) | II(4) | II(16) |
The effect of the derivation upon the learning of the derived series, cannot, as it seems, be essentially affected through this slight change. Here, as in the above described method of derivation, the syllables which during the first learning had been separated from each other by an intervening syllable were learned 24 hours later in immediate succession.
For each number of repetitions used in learning I made 8 double tests, which gave the following results:
Number of repetitions employed for the impression of each of the original series:
| 16 | 64 | |||
| Number of seconds required for learning the six derived series after 24 hours (including the recital): | ||||
| 1178 | 1157 | |||
| 1216 | 982 | |||
| 1216 | 1198 | |||
| 950 | 1148 | |||
| 1358 | 995 | |||
| 1019 | 1017 | |||
| 1191 | 1183 | |||
| 1230 | 1196 | |||
| Average | 1170 | 1109 | ||
| Probable error | 30 | 22 | ||
On account of the small number of experiments the resulting averages are, unfortunately, not very exact; but the general character of the results would remain the same even if we considered the value false within the whole range of the probable error. This character becomes apparent upon comparison with the values given above (p.56) for learning by heart six 16-syllable series which had not previously been learned. This took place in 1,270 seconds. After the original series had been
