Longitudinal studies provide useful and unique data for social science research but are labor intensive and expensive. Key to conducting a successful longitudinal study is the ability to locate respondents in the follow-up effort. We conducted a 35-year longitudinal study among Mexican Americans in Los Angeles, California, and San Antonio, Texas. In this article, the authors describe (a) the individualized approach used in searching and (b) how recent technological developments have provided extensive sources of information that facilitated the searching process. The authors locate 79 percent of their sample. This study differs from previous longitudinal studies in that (a) the population is ethnic, urban, and working class; (b) more than 30 years had passed since the original study; (c) the authors built on a study not originally designed as a longitudinal effort; and (d) there had been no contact with respondents in the intervening period.
Key Words: longitudinal methodology • longitudinal research • locating respondents • Mexican Americans • Hispanics