Calling Rules

Telephone survey researchers often utilize a set of guidelines (or calling rules) that dictate how and when a sample unit should be contacted during the survey's field period. These rules are created to manage the sample with the goal of introducing the appropriate sample elements at a time when an interviewer is most likely to contact a sample member and successfully complete an interview. In telephone surveys, calling rules are typically customized to the particular survey organization and to the particular survey and should be crafted and deployed with the survey budget in mind.

Calling rules are a primary mechanism that researchers can use to affect a survey's response rate. All else equal, making more dialing attempts will lower non-contact-related nonresponse, thereby yielding a higher response rate. In general, the more call attempts placed to a telephone number, the more likely someone will eventually answer the phone, thereby giving the survey organization's interviewers the opportunity to try to complete an interview. However, the trade-off to making more and more phone calls is the additional costs incurred with each call, both in terms of interviewers' labor and the toll charges related to the calls.

Since all surveys have finite budgets and resources that must be allocated for dialing attempts, resources allocated for these purposes cannot be used for other important purposes, such as additional questionnaire testing or development or gathering data from larger sample sizes. This competition for survey resources, along with the tension between achieving higher response rates with more calls made and the added expenditure of these additional call attempts illustrates the importance of a well-thought-out approach to the development and implementation of calling rules to manage a telephone survey sample.

When examining calling rules, an important distinction is often made between first call attempts to [Page 76]a sample member, or cold calls, versus subsequent calls to sample members, or callbacks. The importance of this distinction lies in the different information that is available to the survey researcher to establish calling rules.

In the case of first call attempts, little information exists about the sample member, including no information about the effectiveness of calls previously placed to that sample member. For subsequent call attempts, however, the call history for the sample numbers can be utilized to refine the placement of calls to these sample members. Consequently, calling rules for subsequent calls often differ from the calling rules used to place initial calls.

These calling rules, regardless of whether they apply to first call attempts or subsequent call attempts, can be classified into two different types: ranked category type calling rules and priority scoring type calling rules. Each type denotes an inherent property of calling rules, which is to create some calling order for survey administrators to follow with active samples.