The ability to measure centrality in social networks has been a particularly useful development in social network analysis. For researchers trying to decide which centrality measure is most meaningful and valid for their research purposes, various papers have explored the conceptual foundations of centrality measures. Less well documented is the empirical performance of centrality measures under different research scenarios or constraints. This study uses bootstrap sampling procedures to determine how sampling affects the stability of 11 different network centrality measures. Results indicate that some measures are more stable than others, and that stability is also a function of network and study properties.

Supplementary data are available at Bioinformatics online.

No abstract

Many Demographic and Health Surveys (DHS) in the past decade have queried husbands and wives about their current contraceptive use. In this study, couples' concurrence on use and method used is compared by means of data from 23 countries, mostly in sub-Saharan Africa. Husbands report higher levels of use than do their wives in every country studied, with ranges from 2 percent higher (Brazil) to 150 percent higher (Mali). Many of the discrepancies are the result of husbands' sole reports of periodic abstinence and condom use. Couples with polygynous husbands show less concurrence than do monogamous couples, although the majority of these differences could result from a data-collection problem. Monogamous couples in which one or both spouses reported having extramarital sex partners show less concurrence than do monogamous couples reporting no other partners. Problems of validity of both husbands' and wives' reports are discerned, and in the few instances where a direct comparison is possible, wives' reports are shown to have greater validity. Logistic regression results show that spousal discussion about family planning and greater female education are consistent predictors of concurrence.

The findings from this study show that, over and above IDUs' baseline characteristics, changes in their personal networks are associated with changes in individuals' risky injection behaviors. They also suggest that interventions aimed at reducing HIV risk among IDUs might benefit from increasing IDUs' social contacts with individuals who are not drug users.