Outbound Calling

Telephone calls involving call centers are classified as inbound or outbound, depending on whether the call is being received by the call center (inbound) or initiated in the call center (outbound).

Any telephone survey that starts with a list of telephone numbers involves outbound calling, although telephone surveys often use inbound calling in support functions and can also be entirely inbound.

The list of numbers used might be randomly generated, such as a random-digit dialed (RDD) sample, created from public listings such as the white pages or from prior respondent contact (for example, a customer satisfaction survey might use the phone numbers provided by the customer at the point of purchase).

Particularly with RDD surveys, only a small proportion of dials made will result in live connects, and therefore the efficiency of outbound calling can be significantly improved by using dialer technology. Functions of particular value to conducting outbound surveys include the following:

• 1.
  Autodispositioning, in which the outcome of certain types of calls (e.g. busy, fax, disconnected) can be automatically detected from the signal tones, saving interviewer time and increasing accuracy in the assignment of dispositions, and
• 2.
  Autodialing, where the act of dialing is performed automatically on some trigger, such as

  • A keystroke instruction from an interviewer
  • The interviewer logging into the system or completing an interview, or
  • In the case of predictive dialers, some combination of the probability of a dial being answered and the probability of an interviewer being free to handle a connected call

Outbound calling is often more successful when supported by pre-survey notification to the selected sample, such as by an advance letter sent to numbers in the sample that can be matched to an address. For some numbers that cannot be associated with any postal address, pre-survey notification is still possible using text messaging or pre-recorded voice messages (some dialers have the ability to automatically dial and leave a pre-recorded message on any line that answers), although there have been mixed findings on whether these nonletter forms of pre-notification help or harm response rates.

The use of caller ID is another feature for which there is a varying impact on response rates. Some data suggest that a well-known survey name embedded in the caller ID can help response, and it is known that some exchange systems and household systems will not receive calls that do not have a caller ID associated with them. Other data suggest that households are more likely to answer the phone on a refusal conversion call if the caller ID is suppressed or different from that used on earlier dials. Finally, most calls go through many exchanges between the call center from which the call originates and the target telephone number that can change or transform the ID transmitted, introducing additional uncertainty about the impact of caller ID on the success of an outbound call.