DIALING HABITS OF TELEPHONE CUSTOMERS 



59 



856 922 954 



NUMBER OF OBSERVATIONS 

 892 61 69 65 73 88 326 383 435 



4 8 12 16 4 8 12 16 4 8 12 16 



TIME,t, IN SECONDS AFTER SENDER SEIZURE 



Fig. 16 — Results of sender monitoring observatious. 



with increasing dial tone delay, of the per cent sender seizures resulting 

 in dialing before tone, in dialing after tone and in disconnections for the 

 five dial tone delay intervals studied. 



Some general comments concerning Figs. 13 to 16 may be made. 



1. There is a striking contrast between the message rate and coin 

 classes of service. This may be due to the immediate financial stake 

 that a coin customer has in his call. He is reluctant to disconnect before 

 dial tone. 



2. The results for the message rate and flat rate classes of service 

 appear to be similar at the shorter dial tone delays; at the longer delays 

 a higher proportion of flat rate subscribers have already dialed before 

 dial tone. This apparent discrepancy may be due to the relatively small 

 number of flat rate observations. Flat rate service in Sterling-3 and Main- 

 2 was principally for professional people, such as doctors and nurses, 

 who were thought to be more demanding than ordinary subscribers for 

 prompt dial tone service. These results therefore should not be con- 

 sidered characteristic of fiat rate customers generally. 



3. Detailed analysis of the data (results not presented in this article) 

 indicated that the cUstributions of time to first pulse for subscribers not 

 observing tone, and for those waiting for tone, are quite similar for the 

 three classes of service. 



4. Only the unsmoothed raw data have been shown on Figs. 13 to 

 15 since certain inadequacies were detected in the observations. These 

 were due to observer reactions and reading errors disco\'ered as a result 

 of comparing preliminary practice sender monitor test results with a 

 simultaneous record obtained by the 100 pen tape recorder. The overall 



