vin PRACTICAL JUDGMENT 155 



is due to connected experience, and what is not, would be 

 immensely simplified. But we cannot deny that a single 

 experience without any insight into relation may in some 

 cases form a basis for memory. Thus even a series of 

 meaningless syllables, if not too long, may be retained 

 perfectly for a few moments, after a single hearing. 1 But 

 the effect very speedily lapses. After twenty-four hours, 

 the only result of a number of readings sufficient to get 

 the syllables by heart for the moment is a certain 

 diminution in the number required to get them perfect 

 again. To illustrate the point, it will be enough to give one 

 series of Ebbinghaus's experiments with twelve syllables, 

 comparing it with his results for a stanza. The Roman 

 numerals indicate the successive days ; the Arabic figures, 

 the number of times necessary to get the repetition 

 perfect. 



Days I. II. III. IV. V. VI. 



12 syllables 16-5 n 7-5 5 3 2*5 



Stanza of Don Juan 7*75 3-75 1-75 -5 o o 2 



I may subjoin a further table given by Mr. G. W. 

 Smith, 3 showing the very slow improvement from repeti- 

 tion up to twelve times. Ten syllables were read and 

 repeated. The table shows the number correctly given, 

 and the number of mistakes after a given number of 

 readings. 



Number of Number cor- T . F 



Readings. rectly given. Total Errors ' 



I 2'2 22*2 



3 2-5 21-4 



6 2-8 20-5 



9 3*4 18-9 



12 3-9 17-3 



We may conclude that as we approximate to irrational 

 association in human experience, the number of repetitions 

 required to fix a sequence in memory for any length of 

 time becomes very large. Forty repetitions did not suffice 

 to fix twelve syllables in Ebbinghaus's memory perfectly 



1 Binet and Henri, loc. cit. p. 7. 2 Op. cit. p. 112. 



Psychological Review^ 1896, "The Place of Repetition in Memory." 



