Conducting research among hard-to-reach populations is a difficult endeavor because some of their characteristics are known to be associated with survey nonresponse and panel attrition. In the case of the Parchemins study, which followed undocumented migrants over their process of regularization and during the first years of regularized life in…

This article analyzes whether response patterns in surveys differ between the general population, regular immigrants, and recent refugees. Analyses show that the address quality of refugees contacted in the first wave of a panel study is worse than that of the general population, but of a similar quality to that of other recent immigrants. Once…

Passive data from a tracking application (or "meter") installed on participants' devices to register the URLs visited have great potential for studying people's online activities. However, given privacy concerns, obtaining cooperation installing a meter can be difficult and lead to selection bias. Therefore, in this article, we address…

Increasingly surveys are using interviewers to collect objective health measures, also known as biomeasures, to replace or supplement traditional self-reported health measures. However, the extent to which interviewers affect the (im)precision of biomeasurements is largely unknown. This article investigates interviewer effects on several…