Chapter 7 - Design, Conduct, and Analysis of Random-Digit Dialing Surveys

Abstract

Random-digit dialing (RDD) is a method of probability sampling that provides a sample of households, families, or persons through a random selection of their telephone numbers. For simplicity of explication, the person is used as the final unit of analysis in this chapter; yet, virtually all the comments and methods extend to the household or family. The chapter discusses the design, conduct, and analysis of RDD surveys, primarily in the context of large-scale work performed in the United States. The material generalizes to other countries with an established landline infrastructure. In the United States, there is no sampling frame that enables a direct sampling of persons. RDD changes the sampling unit from the person to the telephone number, for which sampling frames do exist. Then people can be sampled indirectly through their telephone numbers, enabling valid inferences to populations of people. In the modern era, the RDD survey has come to embody the following three elements: (1) random sampling of telephone numbers from a listing of all (or most) assigned telephone numbers, (2) dialing the selected numbers from central call centers, and (3) administering the survey questionnaire to residential respondents through a system of computer-assisted telephone interviewing.