So you want to field a phone study? Perhaps you've used this mode in the past, or maybe this is a brand new avenue for your company. Regardless of whether you are looking to run your first or fifteenth telephone project, the place to start is with sampling methodology.
Rigid sample management: customer lists, random digit dialing, and more
Many companies still rely on telephone data collection for the benefits it offers that more recent modes do not, such as interviewer intervention for richer open-ended response collection, the ability to reach specific population subsets that may be less attainable via the Internet, and the ability to interview customer databases where no email addresses are available.
The sample and sampling process comprise the bedrock upon which the quality of the data collection depends. As the old expression goes, "garbage in, garbage out."
There are multiple sources available for telephone samples, such as: customer lists, business-to-business databases, RDD samples (random digit dialing), address based samples (respondents are reached both through telephone and non-telephone approaches, such as mail or web), wireless samples (cell phone numbers, which must be called without the benefit of a predictive dialer), and demographically targeted lists.
The type of study conducted will dictate the most appropriate form of sample that should be used. Two of the most commonly used sample types are RDD and customer lists.
Characteristics and benefits of RDD:
- RDD is defined as a list of randomly configured 10 digit numbers that but also may be non-usable numbers such as dedicated fax lines, business numbers, non-working numbers, etc.
- It is the cheapest option for purchasing sample, at pennies per phone number
- RDD is a good choice for general population studies with higher incidence rates, and non-branded (blind) studies where the client does not wish the survey responses to be impacted by awareness of the project's sponsor
- When used in conjunction with a predictive dialer to weed out the non-usable phone numbers, an RDD sample can be a very efficient way to reach a broad population
Characteristics and benefits of customer list sample:
- Customer lists are just that, lists provided by the client containing contact information for their customer base, prospect base, or lapsed customer lists.
- Customer lists are ideal for reaching the client's customer base for conducting many types of customer research, including customer satisfaction, attrition studies, and more.
- Customer lists can also be used to obtain appended data (such as age, gender, geographical location) directly from a client database, which offers a deeper view of the study results.
- In some cases, job performance evaluations for company employees are driven in part by the results of customer satisfaction results. In that scenario, it is critical to be able to tie results back to the employee or store/branch who handles a particular customer's account, something that can be assured by using a customer list that contains transactional/customer-level information of this nature.
The sample type selected for a given study can have huge implications for the success of that study, both financially, and on data quality.
The budget for the research and the study objectives should be carefully evaluated between client and research provider to determine which approach will best deliver on budget while not compromising the results.
Ask yourself the following key questions to determine whether your own customer list or RDD sample is the best avenue for your phone market research project.
- Do I want to reach my current customers, lapsed customers, or prospects?
- Do I already have phone numbers for this group?
- Will my research results benefit from the appending of transactional or other customer data that I have available?
If you said yes to some or all of these questions, then your customer list may be the best course. Check with your research provider to be sure.
- What if I want to reach a large group of people and do not have a large number of qualifying questions?
- Am I looking for results that mirror the US population by demographic subgroup such as age, gender, income, etc?
- Do I need to reach the customers of my competitors as well as my own?
In this scenario, you may be better served by using an RDD list or some other non-customer list based sample source such as an address-based sample. In some cases, your research provider may recommend a combination sample approach to most accurately and precisely reach your targets.