Inaccuracy of sociometric reports poses a serious challenge to social network analysis. Nevertheless, researchers continue to draw potentially misleading conclusions from flawed data. We consider two particular types of systematic error in measurement of network size: individuals over/underreporting others (expansiveness bias), and individuals being over/underreported by others (attractiveness ...

We review current practice concerning the use of respondent incentives on longitudinal surveys and we review experimental evidence concerning the effects of incentives on longitudinal surveys, particularly on cumulative response rates and on sample composition. To provide context, we also briefly review the research literature regarding the effects of incentives on cross-sectional surveys and d...

Respondent driven sampling (RDS) is a method often used to estimate population properties (e.g. sexual risk behavior) in hard-to-reach populations. It combines an effective modified snowball sampling methodology with an estimation procedure that yields unbiased population estimates under the assumption that the sampling process behaves like a random walk on the social network of the population....

Respondent-driven sampling is a network-based technique to collect information and make estimation about behavior and composition of social groups in hidden population. The non-randomly selected samples prohibit the use of the sample mean as a statistically valid estimator. Researchers have proposed several asymptotically unbiased estimators, but many fail to realize that the high variance of t...

BACKGROUND Internationally wheelchair users are an emerging demographic phenomenon due to their rapidly increasing life-span coupled with accelerated general population ageing. While having significant healthcare and social implications, basic robust epidemiological information of wheelchair users is often lacking due in part to this population's "hidden" nature. Increasingly popular in epidemi...

The central problem of longitudinal surveys is attrition. The National Longitudinal Survey of Youth in 1979 (NLSY79), which this issue of the Monthly Labor Review features, is the gold standard for sample retention against which longitudinal surveys are usually measured. However, we cannot understand how the NLSY79 has done so well without considering what was done differently in the other coho...