1253 
calculate the gain effected with I and Il in the repetition-experiments 
of the first and the second group. This gain is expressed in percentages 
in the following table. | 
TA BEE 
Observers Groups I II 
Ist 56.15 44,33 
M. 
2d 48.75 51.62 
El | | Ist 51.85 62.20 
2d 36.11 55.72 
EEA DA 45.29 ans 
D. 
2d 54.05 — 
For M and D the gain lessens with I. The learning of the series 
of the second group requires, it is true, fewer repetitions but the 
decrease of the number of repetitions in the repetition-experiments 
does not run parallel to it, so that after all the gain turns out to 
be smaller. D, who sat down for the first time to an experimental 
investigation of the memory, learns the series of the second group 
not only with fewer repetitions, but also furnishes a greater gain in 
the repetition-experiments, a phenomenon due to his inexperience, 
which made him more susceptible than the others to the favourable 
influence of practice and of the repetition of the experiments. 
With “II the influence of practice is noticeable for R in a fall of 
the percentage of repetitions saved; for M however, this percentage 
rises. Most likely the difference between those two observers is due 
to the fact that with II R tried to translate the rate of succession, 
which did not suit him, into his own, in which, of course, he 
sueceeded only after some training. M, on the other hand, scrupu- 
lously stuck to the experimental rate all through the experiments 
with II. 
The influence of practice on the learning-time (Table IX) appears 
for R and D generally in a decrease of the latter. This applies 
to | as well as to II, to the learning- as well as to the repetition- 
experiments. Whereas for R with I the number of repetitions in the 
learning-experiment decreases (33 perc), the decrease in time is 
37,11 pere., for D the decrease is respectively 17,03 perc. and 34 perc. 
For D the number of repetitions with I decreases in the repetition- 
experiments 31,04 perc., the learning-time 39,14 perc., so that here 
also the influence of practice is shown in a shorter learning-time; 
80* 
