506 



THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1957 



Experiment 6: Effect of Phij. biological Utterance Limitations 



One of our best indications that the maximum reading rate of a 

 subject is determined by mental rather than by physical limitations is 

 that discrete word lists were read no faster silently than aloud. This 

 may appear contrary to very high silent reading rates widely fjuoted. 

 This can be explained by the fact that in reading much prose we do not 

 and need not recognize every word in order to get the sense. Presumably, 

 if an author made every word say something, his prose could not be 

 read with understanding at such high rates. 



We can also show in another way that the mere uttering of the N\'ords 

 does not determine the reading speeds observed. A memorized prose 

 phrase ("This is the time for all good men to come to the aid of their 

 country") was repeated several times at rates of 7.5, 9.1 and 8.4 words/ 

 sec for the three readers. 



Fig. 6 compares word rates for repeating a phrase with the word rates 

 previously discussed. The radically faster rate for repeating a phrase is 

 not the only feature to be observed in this figure; the three readers are 

 not in the same order of speed as is preserved through the reading 

 experiments. This would suggest that it is word recognition rather than 

 speaking speed which accounts for differences among the reading rates 

 of different people. 



10 



7 

 O 



§6 



LU 



Q. 



O 4 

 IT 



o 

 5 ^ 



REPETITIVE 

 PHRASE 



PROSE 



SCRAMBLED 



PROSE "PREFERRED" 

 LIST 



READING 



_WHILE _ 



TRACMNG 



READER ABC 



ABC 



ABC 



ABC 



ABC 



Fig. 6 — Effect of physiological utterance limitations. 



