%0 Book Section %B Methodology of Longitudinal Surveys %D 2009 %T Keeping in Contact with Mobile Sample Members %A Mick P. Couper %A Mary Beth Ofstedal %E Lynn, Peter %K Methodology %X In this chapter, we first offer an overview of the location problem, as distinct from other sources of panel attrition or nonresponse. We then offer a framework for understanding the location propensity to guide fieldwork strategies and identify likely sources of bias. Then we briefly describe two cases studies, examining the extent of the location problem and correlates of (non)location. We end with a brief discussion of the changing role of technology in facilitating or impeding the ability to locate sample persons who have moved or changed contact information, and offer some thoughts for research and practice. %B Methodology of Longitudinal Surveys %I Wiley %C New York %P 183-202 %G eng %4 Methodology/Sample Design %$ 62604 %& 11 %R https://doi.org/10.1002/9780470743874.ch11