DIALING HABITS OF TELEPHONE CUSTOMERS 61 



subscriber after receipt of dial tone are noted by breaks in the markings 

 of the hne busy pen. Diahng, hang-up or flashing before dial tone are 

 noted l),y simultaneous breaks in the markings of both pens. Various 

 intervals can be measmxHl and the call attempts classified accordingly. 

 Observations were obtained in the foregoing manner duiing the course 

 of the Sterling-3 line finder tests on the following numi)ers of subscriber 

 lines : 



Message rate — residential 87 



— business 23 



— PBX 12 



— two party 32 



Flat rate individual 7 



Coin 21 



182 



The observed data were classified for each of the above six types of 

 subscribers in terms of the following categories: 



1. Time to subscriber action before receipt of dial tone. 



a. Time from receiver off hook^ to first digit dialed by subscriber. 



b. Time from receiver off hook to disconnecting action by the 

 subscriber. 



2. Time from receiver off hook to receipt of dial tone. 



3. Time to subscriber action after receipt of dial tone. 



a. Time from receipt of dial tone to first digit dialed by subscriber. 



b. Time from receipt of dial tone to disconnecting action by the 

 subscriber. 



Because the data developed in this section are compared with both 

 the j factor analysis and the sender monitor test results and because 

 the treatment of subscriber dialing habits before dial tone for each of 

 these items is different, categories la and lb are analyzed in two ways. 

 In the j factor analysis, all actions of a subscriber prior to dial tone, 

 except a disconnect, were considered to be one continuing demand for 

 service. Thus for the first analysis, cases of dialing, flashing and short 

 disconnections before tone lasting less than three seconds were ignored. 

 In the sender monitor tests the only items considered were the time to 

 the first digit dialed by a subscriber and the time, if no dialing occurred- 

 to the release of the sender by the subscriber. Thus for the second analy- 

 sis, cases of dialing before tone and flashing or disconnections before tone 



'When a customer initiates a call, the line relay operates. For individual line 

 and two-party subscribers this occurs when the subscriber takes his receiver off 

 the hook. For coin customers this occurs when the customer has taken his re- 

 ceiver off the hook and made a proper deposit. For a PBX line this occurs when 

 the PBX attendant has established a connection to an outside line. All of this 

 is collectively termed "receiver off hook." 



