1250 
TABLE VII. Observer D. 
Groups Arithm. mean Mean deviation Median 
pike: 11.09 1.33 | 10.62 
st] 
| r 9.82 1.49 9.70 
I aes 10.70 1.33 10.35 
C2 [cet Did 
(20) | Le ise 10.12 1.74 9.55 
| | (| 1 11.49 1.89. 11.13 
3d || 
Elve 10.11 1.58 10.25 
ri 9.76 0.53 9.76 
Ist | 
| Bi 9.53 0.22 9.51 
Il 1 9.69 0.59 9.58 
cee | | | 
(8) | EE: 9.22 0.37 9.22 
rea | 9.67 0.67 9.50 
‘| ad | | 
| or 9.33 0.42 9.31 
| 
the repetition-experiments. Again with one exception for D the 
increase is greater in the repetition- than in the learning-experiments 
(for M. 3.89 and 2.78; for R. 2.77 and 1.71 sec); this proves again 
that with at least two of our observers there is a tendency to 
lengthen the learning-time, when the knowledge of the material has 
increased in consequence of the repetition-experiments of the 
previous day. It is also proved by the- fact that with a few excep- 
tions, the lengthening of the learning-time, in the learning- as well 
as in the repetition-experiments is greater when passing from the 
IId to the [Id than from the Ist to the IId group. (for M. 1.13 and 165 ;1.44 
and 1.95 ‘sec.; for KR. 0.91 and 0.80:- 0.19 -and 2.81; sec; tor 
D.: —0.39 and 0.79; 0.30 and — 0.01 sec.) It seems advisible to 
conclude, therefore, that with I for two of our three observers the 
time required for succession-repetitions increases as well in the 
learning- as in the repetition-experiments, when the observer gets 
more familiar with the material. With Il there is no gradual increase 
at all with a fuller knowledge of the material. As with I, the time- 
values are indeed, generally smaller in the repetition- than in the 
learning-experiments, but where, as e. g. with I the mean duration 
of the repetition of the last group is always the longest, it is always 
the shortest with group II, with a few exceptions only. For the 
