1245 
The last column illustrates the gain (expressed in percentages) realised 
after 24 hours by the natural- and by the experimental meihod. 
We also add a column for the number of series learned by heart. 
TASB iE at, 
Number Arithm. Mean Gain after 
Observer "| of series mean deviation Median 24 hours 
| 
| | 
| 8.45 1.50 8 
20 I 52,71 
if 4 0.46 4 | 
M. | 
1 9.25 1.41 9 | 
20 II | | 47.03 
r 4.90 0.95 a} 
\ | 4.50 1.04 4 | 
20 I 45.56 
ieee 2.45 0.78 RER 
R. | 
| 7.60 1.50 [0 | 
20 II | 35021 
Fr 3.10 0.74 3 
| 9.66 2.08 9 
20 I | 49.28 
| r 4.90 0.80 5.50 
D. 
| | 10.50 3.25 9.50 
8 II 46.43 
| fr 5.60 1.92 4.50 
The order of the observers relative to the number of repetitions 
in group I is maintained in group IJ. For each of them the number 
of the repetitions increases; for M. and D. in about the same degree 
(respectively 9,47 and 8,69 percent); for R the increase is much 
greater (68.89 perc.). A similar process is observed in the 7-rows. 
Here also the increase is greatest for R (26.53 perc.), much less for 
D than for M (respectively 14.28 and 22.5 perc.). 
The percentage of repetitions saved after 24 hours is for M and 
D higher in I than in II (respectively 52.77; 47.03 and 49.28 ; 
46.43 perc). The reverse is observed in the case of R, for whom 
Il yields a considerably larger gain (59.21 and 45.56 perc.). 
The second Table gives the average time required for getting a 
series by heart in group I and II. After what we said about the 
preceding table we need not enter into further details about its 
construction. The time-values are expressed in seconds. 
With II the time of the learning-experiments decreases, for M 
and D respectively 5.28 and 14.74 pere. R, however, requires more 
