Geo-Sampling: Refining the Grid-Based Sampling Method Using Geographic Information Systems Layers and Spatial Data

• Activity Number: 251
• Type: Contributed
• Date/Time: Monday, August 10, 2015 : 2:00 PM to 3:50 PM
• Sponsor: Survey Research Methods Section
• Author(s): Safaa Amer and Justine Allpress* and Mark Bruhn and James Cajka
• Companies: RTI International and RTI International and RTI International and RTI International
• Keywords: Geo-Sampling ; Multi-national Survey ; Sampling ; GIS ; Design

Abstract

RTI International is currently performing a multi-national survey requiring the identification of residences that are accessible to interviewers and provide an appropriate demographic cross section. To meet this challenge, RTI designed a grid based sampling method that uses inputs from multiple Geographic Information System (GIS) layers and available spatially defined demographic data. Compiling the geospatial and census data for the sampling process has proven particularly complex due to the inconsistency of readily available data across countries and the variability of administrative structure. The methodology, while transferable to all countries, needs to be elastic to allow tailoring for spatial and temporal differences between areas. In addition, RTI has researched the availability and effectiveness of geospatial data layers, to improve the design for operational reasons. Strategies used include ways to minimize the inclusion of non-residential areas, plan for difficult to access areas, and account for exclusions due to security. These enhancements have the potential to greatly increase data collection efficiency and reduce the need to supplement the sample during field work.