Challenges of Virtual RDS for Recruitment of Sexual Minority Women for a Behavioral Health Study

Respondent-driven sampling (RDS) is an approach commonly used to recruit nonprobability samples of rare and hard-to-find populations. The purpose of this study was to explore the utility of phone- and web-based RDS methodology to sample sexual minority women (SMW) for participation in a telephone survey. Key features included (i) utilizing a national probability survey sample to select seeds; (ii) web-based recruitment with emailed coupons; and (iii) virtual processes for orienting, screening, and scheduling potential participants for computer-assisted telephone interviews. Rather than resulting in a large diverse sample of SMW, only a small group of randomly selected women completed the survey and agreed to recruit their peers, and very few women recruited even one participant. Only seeds from the most recent of two waves of the probability study generated new SMW recruits. Three RDS attempts to recruit SMW over several years and findings from brief qualitative interviews revealed four key challenges to successful phone- and web-based RDS with this population. First, population-based sampling precludes sampling based on participant characteristics that are often used in RDS. Second, methods that distance prospective participants from the research team may impede development of relationships, investment in the study, and motivation to participate. Third, recruitment for telephone surveys may be impeded by multiple burdens on seeds and recruits (e.g., survey length, understanding the study and RDS process). Finally, many seeds from a population-based sample may be needed, which is not generally feasible when working with a limited pool of potential seeds. This method may yield short recruitment chains, which would not meet key RDS assumptions for approximation of a probability sample. In conclusion, potential challenges to using RDS in studies with SMW, particularly those using virtual approaches, should be considered.

Risk of Nonresponse Bias and the Length of the Field Period in a Mixed-Mode General Population Panel

Survey researchers are often confronted with the question of how long to set the length of the field period. Longer fielding time might lead to greater participation yet requires survey managers to devote more of their time to data collection efforts. With the aim of facilitating the decision about the length of the field period, we investigated whether a longer fielding time reduces the risk of nonresponse bias to judge whether field periods can be ended earlier without endangering the performance of the survey. By using data from six waves of a probability-based mixed-mode (online and mail) panel of the German population, we analyzed whether the risk of nonresponse bias decreases over the field period by investigating how day-by-day coefficients of variation develop during the field period. We then determined the optimal cut-off points for each mode after which data collection can be terminated without increasing the risk of nonresponse bias and found that the optimal cut-off points differ by mode. Our study complements prior research by shifting the perspective in the investigation of the risk of nonresponse bias to panel data as well as to mixed-mode surveys, in particular. Our proposed method of using coefficients of variation to assess whether the risk of nonresponse bias decreases significantly with each additional day of fieldwork can aid survey practitioners in finding the optimal field period for their mixed-mode surveys.

Exploring the Feasibility of Recruiting Respondents and Collecting Web Data Via Smartphone: A Case Study of Text-To-Web Recruitment for a General Population Survey in Germany

The widespread usage of smartphones, as well as their technical features, offers many opportunities for survey research. As a result, the importance and popularity of smartphone surveys is steadily increasing. To explore the feasibility of a new text-to-web approach for surveying people directly via their smartphones, we conducted a case study in Germany in which we recruited respondents from a mobile random digit dialing sample via text messages that included a link to a web survey. We show that, although this survey approach is feasible, it is hampered by a number of issues, namely a high loss of numbers at the invitation stage, and a high rate of implicit refusals on the landing page of the survey.