Transitioning a panel survey from in-person to predominantly web data collection: Results and lessons learned

Over the last two decades, in-person interviewing costs continued to increase while the data quality advantages traditionally identified with this data collection mode have faded. Consequently, some longitudinal surveys have begun transitioning from in-person to web data collection despite risks to data quality and longitudinal comparability. This paper addresses the major issues involved in the transition process and proposes a multi-sample, multi-phase responsive design that attempts to minimize the data quality risks while preserving the considerable cost savings promised by the transition. The paper describes the design as it was applied to the National Longitudinal Study of Adolescent to Adult Health (Add Health)-a nationally representative panel survey of around 20,000 adolescents selected from grades 7 to 12 (typically 13 to 18 years of age) in the 1994-95 school year. Also described are key results from several experiments embedded within the design and the analysis of mode effects. Also presented are some lessons learned and recommendations for other in-person panel surveys that may be contemplating a similar transition to web or mixed-mode data collection.