DIALING HABITS OF TELEPHONE CUSTOMERS 



57 



the li^-potlictical surxivor curve C for inlinitel}- delayed dial lone. This 

 indicates that most of the subscribers who would have abandoned their 

 attempts durinjj; this in(er\'al abruptly changed their minds and then 

 consumed a noticeable interval of time after hearing tone before start- 

 ing to dial. Thus, as might be anticipated, the subscribers exhibit a 

 reaction time. 



Fig. 13 shows the results in terms of survivor curves that were ob- 

 served for the message rate class of service. Five sets of curves are 



■^ 3\^i\L A9 NOIiOV N3><V1 iON 3AVH OHM Sa39mDS9nS dO iN30 HSd 



