This study aims to examine time-dependent effects of group-level relational composition, including the number and cohesion of prior online relationships and multiple-group membership (MGM), on the success of online wellness challenge groups (OWCGs) in promoting positive health behavior among group members. Bridging literature on online groups and social networks for health, this study collected data on 1,252 OWCGs and conducted analyses on how relational composition affected group success longitudinally over the life span of the OWCGs. The results showed that the number of prior online relationships within a group had a positive but decreasing effect over time on group success, whereas cohesion was not a significant predictor. MGM, indicating members' concurrent participation in multiple OWCGs, showed a positive effect on group success at the beginning but a negative effect towards the end of a group's life span. Theoretical and practical implications for designing successful OWCGs were discussed.

中文翻译：

---

关系构成对在线健康挑战小组成功的时间依赖性

这项研究的目的是检验群体水平关系组成的时间依赖性影响，包括先前在线关系的数量和凝聚力以及多组成员身份（MGM），对在线健康挑战组（OWCG）成功促进积极健康行为的影响在小组成员中。结合在线团体和健康社交网络的文献，本研究收集了1,252个OWCG的数据，并进行了分析，分析了关系构成如何在OWCG的整个生命周期内纵向影响群体成功。结果表明，组中先前在线关系的数量对组成功有积极但逐渐降低的影响，而凝聚力并不是重要的预测指标。米高梅代表会员同时参与多个OWCG，在开始时对团队成功产生积极影响，但在团队寿命结束时却表现出负面影响。讨论了设计成功的OWCG的理论和实践意义。