THE WORDS AND SOUNDS OF TELEPHONE CONVERSATION 293 



which show, for two classes of words, the way in which the number of 

 different words in each class varied as the total number of words in 

 that class increased. To take the nouns, of the first 200 about half 

 were different, of the first 1,000 about a third were different, of the 

 total of 11,660 nouns recorded about one tenth were different. An 

 extrapolation of the curve indicates that the observations would need 



2000 



(/) 

 Q 

 CC 

 O 



5 



I- 

 z 



UJ 



a 

 u 



u. 



o 



1000 



500 



i 100 



z 



50 



100 



1,000 10,000 



TOTAL NUMBER OF WORDS IN EACH CLASS 



100,000 



Fig. 1 — The number of different words occurring in a given total number of words, 

 for nouns and for verbs. 



to be increased tenfold from this point in order to double the number 

 of different nouns. Approximately the same extension of the ob- 

 servations would be required to double the number of different verbs. 

 In neither case, however, could a material change in the relative oc- 

 currence of the speech sounds be expected if the observations were so 

 extended. This will be shown below. 



Table II shows the total number of words and the number of dif- 

 ferent words for each part of speech separately. The verbs and aux- 

 iliary verbs, which were recorded together, have been separated in the 

 table. The numbers of total words for the other three minor classes 

 have been found by multiplying the observed figures by the ratio of 500 

 to the actual number of conversations (about 150) on which observa- 

 tions were made for these classes. The numbers of different words for 

 these classes are not similarly increased since virtually all the possible 

 different words were obtained in the observations. In finding the 

 number of different words the various forms of the words, such as the 

 plural form of the nouns, the different tenses of the verbs, and the 

 comparative and superlative forms of the adjectives, have not been 

 counted as separate words, although they were recorded and are 



