Like many medical studies, the Berlin Aging Study II (BASE-II) is based on a non-random convenience sample of self-recruited participants. To study processes of selectivity in BASE-II, we used an identical questionnaire to compare BASE-II with a large, representative reference study, the German...

In this paper we discuss the rationale for tracing non-original sample members (Non-OSMs) in household panel studies, and in particular in SOEP, and the implications for weighting. We present results on the incidence, survival rates, and thus the relevance of Non-OSMs in the SOEP

Since it is still unclear to what extent time allocation retrospectively reported in questionnaires, reflects people's actual behavior, examining the accuracy of responses to time use survey questions is of crucial importance. We analyze the congruence of time use information assessed through...

The Berlin Aging Study II (BASE-II) is a multidisciplinary study that allows for the investigation of how a multitude of health status factors as well as many other social and economic outcomes interplay. The sample consists of 1,600 participants aged 60 to 80, and 600 participants aged 20 to...

Interest in the effects of sleeping behavior on health and performance is continuously increasing-both in research and with the general public. Ecologically valid investigations of this research topic necessitate the measurement of sleep within people's natural living contexts. We present...