A Mixed Method Approach to Sample Design

Barbara Entwisle, University of North Carolina at Chapel Hill
Allan Parnell, Cedar Grove Institute for Sustainable Communities
Philip McDaniel, University of North Carolina at Chapel Hill

Sample designs for personal interview surveys typically rely on census geography for definitions of primary and secondary sampling units. This paper proposes an alternative approach to the definition of sampling units at a local level that combines community engagement with analysis and maps created within a GIS and illustrates this approach with examples from the definition of secondary sampling units (segments) within the National Children's Study (NCS). The NCS follows a stratified multistage cluster design. Within the 105 counties that serve as the primary sampling units, there is flexibility to incorporate community input into the definition of secondary sampling units. This paper describes the scientific and operational reasons for community involvement at this stage and draws on recent experience in three study locations in North Carolina to show how it can be done.